troubleshooting

Refer to the exhibit. How many physical disks are detected by the kernel, and what are their sizes?

A senior administrator runs a script that processes a CSV file. The script contains the following snippet: 'for field in $(cat data.csv); do ...'. The data.csv file contains lines like: 'John Doe, 123 Main St, Springfield'. The script fails to process correctly, splitting fields incorrectly and causing errors. Which of the following is the most appropriate fix?

You manage a CentOS 7 server that runs a critical application storing data on an XFS filesystem mounted at /data. The server experiences an unexpected power outage. After rebooting, the application fails to start, and you suspect filesystem corruption. You boot into single-user mode and attempt to mount /data, but the mount fails with an error: 'mount: /dev/sdb1: can't read superblock'. You run 'xfs_repair -n /dev/sdb1' and it reports the log is dirty and must be replayed or the filesystem repaired with the -L option (force log zeroing). You want to recover the filesystem with minimal data loss. Which action should you take?

A DHCP server assigns IP addresses to clients, but some clients are not receiving the correct gateway. Which configuration file should be checked on the DHCP server?

A Linux system has multiple disk partitions. The administrator wants to view the UUID of a specific partition for use in /etc/fstab. Which command will display the UUID?

A small office server running Ubuntu 20.04 experiences a gradual time drift. The system clock loses about 2 minutes per week. The hardware clock (RTC) is maintained by the motherboard battery and appears accurate when checked manually. The sysadmin wants to ensure the system clock stays synchronized automatically. Which single action should be taken? Options: A) Run 'timedatectl set-ntp true' to enable systemd-timesyncd, B) Add 'hwclock --hctosys' to /etc/rc.local, C) Install and configure the ntp package with a pool server, D) Use 'cron' to run ntpdate every minute.

A system is experiencing frequent crashes. Investigation shows that the root filesystem is mounted with 'errors=remount-ro'. The admin wants to prevent data loss by mounting with 'errors=panic' in /etc/fstab. Which change is correct?

Refer to the exhibit. The process with PID 1234 is in state 'Z'. What is the most likely cause and appropriate action?

Match each device file naming pattern to its device type.

A system administrator wants to configure log rotation to compress log files daily and keep 30 days of logs. Which of the following configurations achieves this goal?

Which hardware component uses a unique address to identify itself on the network at the data link layer?

An administrator wants systemd-journald logs to persist across reboots. What must be created?

A systems administrator needs to change the permissions of the file /home/user/script.sh so that the owner can read, write, and execute; the group can read and execute; and others have no access. Which command accomplishes this?

On a systemd-based system, which file is NOT used for system initialization?

An Ubuntu 20.04 server needs a static IP address. The administrator has created a netplan YAML file at /etc/netplan/01-netcfg.yaml. What is the next step to apply the configuration?

Which THREE of the following are correct features of the 'grep' command? (Choose three.)

Refer to the exhibit. After modifying /etc/default/grub to enable serial console output, which command must be run to apply the changes to the GRUB configuration?

A company maintains a private Debian repository for internal packages. A new package 'internal-tool' version 2.0 has been added to the repository, but when users run 'apt-get update && apt-get install internal-tool', the old version 1.0 is still being offered. What is the most likely cause?

You are a Linux administrator for a company that uses a custom RPM-based distribution. The development team has built a new version of the internal tool 'monitor-app' (version 2.0) and placed the RPM package in a local YUM repository located at http://internal.repo/monitor-app-2.0.el7.x86_64.rpm. The repository metadata has been updated using 'createrepo'. On a test server running CentOS 7, you run 'yum update monitor-app' but the system reports 'No packages marked for update'. The currently installed version is 1.0. You verify that the repository is enabled and accessible via 'yum repolist'. What is the most likely cause and the correct course of action?

After a system upgrade, the server fails to boot with the error: 'ERROR: Failed to mount the real root device.' The root filesystem is on an LVM logical volume. Which recovery step is most appropriate?

Refer to the exhibit. Which filesystem will be checked last during system boot by fsck?

A technician needs to add the official Debian repository for the 'buster' release. Which line should be added to /etc/apt/sources.list?

Which TWO commands can be used to display the current runlevel of a system?

A sysadmin wants to ensure a specific kernel module is automatically loaded at boot. Which method is considered best practice?

A system administrator is troubleshooting a Linux server that fails to boot. The server has a software RAID 1 configuration using mdadm, with the root filesystem located on /dev/md0. During boot, the system halts with the following error: 'VFS: Unable to mount root fs on unknown-block(0,0)'. The admin verifies that the BIOS recognizes all disks and that the RAID array was properly assembled prior to the last shutdown. The system was working after a recent kernel update, but now fails. Which of the following actions is the most likely solution?

A company manages a cluster of 50 web servers running Ubuntu 20.04. The servers are configured to synchronize time with an internal NTP server at 10.0.0.100 using the default ntpd. The NTP server itself syncs with external stratum 2 servers. Recently, the security team implemented a restrictive iptables firewall on all servers, allowing only essential services. Several servers in the 10.0.1.0/24 network now report time drift and ntpq -p shows all peers with '?' status. A network engineer runs tcpdump on one affected server and sees no NTP replies from 10.0.0.100. The NTP server's firewall is configured to allow inbound NTP from 10.0.0.0/24 only. The engineer also notes that the server's /etc/ntp.conf contains the line 'restrict 10.0.0.100' (which is incorrect) and that ntpq -crv shows 'sync target not reachable'. Which single action will most directly resolve the synchronization issue for the affected servers?

A system administrator needs to find out which package installed the file /usr/bin/foo on a Red Hat system. Which command should be used?

Refer to the exhibit. A user tries to execute a script on a mounted filesystem but gets a permission denied error. The script has execute permissions. What is the most likely cause?

Refer to the exhibit. An administrator wants to add a new partition that uses the remaining space on /dev/sda (total 40GB). What is the next free sector for the start of the new partition?

Match each networking tool to its primary use.

On a modern Linux system using systemd-networkd for interface management and systemd-resolved for DNS, which THREE files are typically involved in network configuration and DNS resolution?

A Linux administrator is troubleshooting a server that fails to boot with the error 'Give root password for maintenance (or press Control-D to continue)'. The root filesystem is on /dev/sda2, formatted as ext4. The administrator suspects a filesystem inconsistency. The server is in a remote data center and the administrator has console access via IPMI. Which of the following is the safest procedure to repair the filesystem?

Refer to the exhibit. The administrator wants to ensure that SSH service starts automatically after a system reboot. Based on the output, what is the current status of this setting?

Which TWO commands can be used to display the current routing table on a Linux system?

Refer to the exhibit. A user gets this error when running a script. What is the most likely cause?

A system administrator needs to install a local Debian package file named 'myapp.deb'. Which command should be used?

A system administrator notices that after updating the kernel, the system fails to boot. The administrator wants to boot the previous kernel. Which GRUB menu option should be selected?

A system fails to mount an XFS filesystem with the entry in /etc/fstab. The entry looks correct. Which fstab field might be missing or incorrect?

A kernel module fails to load with the error 'modprobe: FATAL: Module xyz not found in directory /lib/modules/$(uname -r)'. What is the most likely cause?

Which command is used to compress a file with the highest compression ratio?

Which FHS directory contains essential binaries needed for booting and repairing the system, even before /usr is mounted?

Order the steps to recover a forgotten root password on a Linux system.

Refer to the exhibit. A user reports that the 'myapp' command fails to run. Based on the output, what is the most likely cause?

A script reads a CSV file where fields may contain commas within quoted strings. Which approach correctly parses such fields?

Which THREE of the following are valid runlevels in a traditional SysV init system? (Choose three.)

A cron job is configured to run a script every day at 2:30 AM. The sysadmin notices the job runs but produces no output. Which is the most likely reason?

A developer asks the system administrator to configure a local web server for testing using Apache. The server should serve files from /var/www/test. Which directive must be set in the Apache configuration to set this document root?

A production server running CentOS 7 has multiple SCSI disks (sda, sdb, sdc) configured in a RAID5 array managed by mdadm (md0). The root filesystem is on md0. After a power failure, the server boots but drops into a rescue shell with the error: 'md: md0: cannot run array. Not enough devices online.' The admin checks with 'cat /proc/mdstat' and sees that only sda and sdb are spares (marked as (S)), sdc is missing. Which sequence of commands should the admin use to attempt recovery and bring the system to a functional state? Options: A) First run 'mdadm --manage /dev/md0 --add /dev/sdc', then 'mdadm --run /dev/md0'. B) Boot from a live CD, then run 'mdadm --assemble --scan' to reassemble. C) Run 'mdadm --stop /dev/md0', then 'mdadm --assemble /dev/md0 /dev/sda /dev/sdb /dev/sdc'. D) Run 'mdadm --run /dev/md0' to force start the array in degraded mode, then add sdc with 'mdadm --add' after system is up.

Refer to the exhibit. The root partition is at 80% usage. Which action would reduce usage the most?

A company runs a web server using Apache with multiple virtual hosts. The administrator needs to restrict access to a specific virtual host based on the client IP address. Which configuration directive should be placed inside the <VirtualHost> block to deny IP 192.168.1.100?

An administrator adds the line 'DenyUsers john' to /etc/ssh/sshd_config and restarts the SSH service. What is the effect?

Which TWO commands can be used to display information about the CPU(s) in a Linux system? (Choose two.)

A system administrator needs to remove a package called 'apache2' from a Red Hat Enterprise Linux system while leaving its configuration files intact. Which command accomplishes this?

You are responsible for maintaining a legacy Red Hat Enterprise Linux 6 server that hosts an internal web application. The application was compiled years ago and relies on an old version of OpenSSL (0.9.8). Due to a security audit, you must update OpenSSL to 1.0.1 but the application fails to run with the new version. The vendor no longer supports the application. You must keep the system secure while keeping the application operational. You have access to the application source code but cannot modify it. What is the best solution?

Refer to the exhibit. An admin attempts to execute a shell script located in /tmp but gets 'Permission denied'. Which mount option is most likely causing this?

An RPM-based system has a package 'example-1.0' installed, but a newer version 'example-2.0' is available in a repository. Which command will upgrade the package?

A server configured with UEFI firmware and GPT partitioning fails to boot after a GRUB package update. The administrator suspects the bootloader is not correctly installed. Which command should be used to reinstall GRUB to the EFI system partition?

A script starts multiple background processes. An administrator wants to wait for all background jobs to complete before proceeding. Which command should be used?

When writing a Bash script, which two constructs can be used to safely iterate over a list of filenames that may contain spaces or special characters? (Choose TWO)

A Linux system using systemd fails to reach the default target after a recent change. The administrator wants to boot into a minimal environment to troubleshoot. Which kernel parameter should be added at the GRUB prompt?

Based on the lsblk output, which of the following is true?

An RPM-based system reports a file conflict during package installation. Which option to the rpm command will allow the installation to overwrite files from another package?

A Linux system administrator is tasked with setting up a new server that will host multiple virtual machines using KVM. The server has 64 GB of RAM and two physical CPUs, each with 8 cores (16 threads). The administrator needs to allocate resources efficiently. The VMs will have varying workloads. The administrator wants to ensure that the host system has enough resources for itself and that VMs can use all available CPU cores. Which approach should the administrator take to configure CPU allocation for the host and VMs?

A system administrator wants to monitor a log file in real-time for lines containing 'ERROR' and write them to a separate file. Which command combination is most appropriate?

Which two commands can be used to display the amount of free and used memory in the system?

Refer to the exhibit. The system has two network interfaces: eth0 and eth1. Which interface will be used to reach a host at IP address 10.10.10.10?

A Linux administrator is responsible for a server that runs a critical database application. The server uses SysV init and the current runlevel is 3. The administrator needs to schedule a maintenance window for next Sunday at 2:00 AM to apply security patches that require a reboot. The administrator wants to ensure that after the reboot, the system returns to runlevel 3 and the database service (db_service) starts automatically. The administrator also wants to log the maintenance actions to /var/log/maintenance.log. Which of the following is the BEST approach to accomplish these tasks?

Which THREE of the following commands can be used to display information about block devices?

Which TWO utilities can be used to check and repair an XFS filesystem?

Based on the exhibit, what is the most likely cause of the SSH service failure?

You are a Linux consultant hired by a university IT department. They have a custom scientific application that must be compiled from source on a cluster of identical workstations running Ubuntu 20.04. The compilation process requires a specific version of a library (libfoo 1.2) that is not available in the standard repositories, but an older version (libfoo 1.0) is available. You must provide instructions for installing libfoo 1.2 without breaking the system. The workstations have no internet access to external repositories; they can only access an internal repository. You have the source code and a .deb package for libfoo 1.2 built previously. Which approach would you recommend?

Which two commands can be used to list all packages that have the string 'kernel' in their name on a Debian system? (Choose two.)

Which THREE of the following are true regarding the use of systemd-networkd for network configuration? (Choose three.)

Refer to the exhibit. An administrator notices that /proc is mounted with 'noexec'. What is the impact of this mount option?

A Debian system has some partially installed packages due to a failed installation. Which TWO commands can help resolve the broken dependencies? (Choose exactly two.)

After modifying the /etc/fstab file, an administrator runs the command mount -a and receives the error 'mount: /data: special device /dev/sdb1 does not exist'. What is the most likely issue?

The exhibit shows output from an RPM query on a RHEL 8 system. The installation time is shown as a Unix timestamp. Which command would display the installation date of the openssh-server package in a human-readable format?

A server has a backup script that runs daily at midnight. The system administrator notices that the script sometimes fails because the filesystem is mounted read-only. Which approach is the best practice to ensure the script runs only when the filesystem is writable?

A technician needs to remove a package named 'apache2' along with its configuration files from a Debian system. Which command should be used?

Which TWO of the following are valid methods to run a shell script named 'script.sh' using the bash shell, assuming the script has execute permission? (Choose two.)

Refer to the exhibit. An administrator runs ss -tuln and gets the output above. Which of the following statements about this server is true?

Match each SELinux context component to its purpose.

Which three options are valid ways to install a package 'curl' on a RHEL 8 system? (Choose three.)

Which TWO commands can be used to display the contents of a compressed text file (e.g., .gz, .bz2) directly to standard output without decompressing to disk?

Match each Linux runlevel to its typical description.

Order the steps to add a new user to the system and grant sudo privileges.

An organization uses a custom YUM repository. After adding a new RPM package to the repository, clients running 'yum update' do not see the new package. The repository metadata was regenerated using 'createrepo'. What is the most likely reason the clients are not seeing the update?

After a reboot, a server fails to obtain an IP address on its sole ethernet interface. The administrator checks /etc/netplan/01-netcfg.yaml and finds the configuration looks correct. However, the interface shows no IP. The system uses systemd-networkd. Which command should be run next to apply the configuration and bring up the interface?

Refer to the exhibit. An administrator wants to unset the BASH_ALIASES associative array. Which command will correctly remove it?

Refer to the exhibit. The system has multiple SAS drives attached to this controller, but one of them is not detected during boot. Which command is most likely to provide information about the device detection order?

Which configuration file is the primary configuration file for logrotate?

Which TWO of the following are valid methods to view kernel messages on a systemd-based system?

Which TWO commands can be used to set the default boot target (runlevel) in systemd?

A script uses a while loop to read lines from a file, but a variable set inside the loop is empty after the loop finishes. What is the most likely cause?

An administrator needs to monitor real-time network bandwidth usage on a Linux server. Which two tools are specifically designed for this purpose? (Choose two.)

Which directory in the Filesystem Hierarchy Standard (FHS) contains essential user command binaries that are needed in single-user mode?

A system administrator runs the command `fdisk -l` and sees the following line: Disk /dev/sda: 1000 GB, 1000204886016 bytes, 1953525168 sectors Based on this output, which statement is true?

A system administrator wants to display all lines in /var/log/syslog that do NOT contain the string 'error'. Which command accomplishes this?

A junior admin is tasked with configuring network bonding on a Debian server with two Ethernet interfaces, eth0 and eth1. The goal is to provide link redundancy using active-backup mode. The admin edits /etc/network/interfaces and adds configuration for bond0 with slaves eth0 eth1, then runs 'ifup bond0'. However, the bond interface fails to come up and the error message indicates that the 'bond' kernel module is not loaded. The admin checks with 'lsmod | grep bonding' and finds no output. Which additional step is required to successfully bring up the bond interface? Options: A) Run 'modprobe bonding' before ifup, B) Use ifenslave directly after ifup, C) Reboot the system to load the module, D) Add 'auto bond0' in /etc/network/interfaces.

Order the steps to configure a Linux system to use a proxy server for HTTP.

Which TWO commands are used to manage Debian packages? (Choose two.)

A database server with high I/O requirements needs a filesystem layout optimized for performance. The server has four identical 500GB SSDs. Which design best balances performance and reliability, considering the need to separate transaction logs from data files?

Refer to the exhibit. Which file system is full and what is the likely consequence if the administrator does not take action?

You are a system administrator at a hosting company. A customer reports that their website hosted on a shared LAMP server is returning error 500. The server runs Ubuntu 22.04 with Apache, MySQL, and PHP. You log in and find that the /var partition (on /dev/sda3, ext4) is almost full. You identify that the MySQL database directory /var/lib/mysql contains several large binary logs that are no longer needed. You delete the binary logs using 'rm -f /var/lib/mysql/mysql-bin.*'. However, the available space does not increase. You also notice that an inode leak is suspected. You check inode usage with 'df -i' and see that the partition has plenty of free inodes. You then check with 'lsof | grep deleted' and see several entries for mysqld holding deleted files. What is the correct procedure to free the space?

Refer to the exhibit. When will the backup script run?

A log file access.log contains multiple entries per IP address. An administrator wants to display a list of unique IP addresses sorted by frequency (most frequent first). Which command pipeline achieves this?

A technician runs 'blkid' and sees output like '/dev/sda2: UUID="abc-def-ghi" TYPE="ext4"'. Which command can mount this partition using its UUID?

After receiving a compressed tarball archive.tar.gz from a colleague, you want to list its contents without extracting. Which command should you use?

A user complains that a filesystem is reporting 'Disk quota exceeded' even though the user has not stored any new files recently. What could be the cause?

A DevOps engineer is setting up an automated build pipeline for a Python application on a Debian system. The application must be packaged into a .deb for deployment. The engineer writes a Makefile that creates the package but the final 'dpkg -i' step fails due to unmet dependencies: the application requires python3-requests >= 2.0, but the repositories provide 1.0. The team has a local mirror with custom packages including python3-requests 2.0. The mirror is correctly listed in /etc/apt/sources.list. The engineer runs 'apt-get update' before building, but the dependency resolution still fails. What is the most likely cause?

A system is running out of disk space on /var. The administrator finds that /var/log/syslog is 4GB. Which of the following is the best course of action to prevent future issues while keeping recent logs?

On a Debian-based system using ifupdown, which file should be edited to configure a static IP address for an interface?

Refer to the exhibit. The system administrator wants to determine which package provides the file /etc/passwd. Based on the output, which command would be most appropriate to find the package?

A system administrator notices that the system time is incorrect by several minutes. Which command should be used first to check the status of NTP synchronization?

An administrator notices that SSH connections to a remote Linux server are timing out. After confirming network connectivity, which command should the administrator run on the server to check whether the SSH daemon is actively listening?

After connecting a USB device, the system does not create a device node in /dev. Which command can be used to trigger udev to re-evaluate the device?

A developer has a directory /home/user/project with many files and subdirectories. They need to change the group ownership of all .txt files to 'developers' and set permissions to 640. Which single command accomplishes this?

Which THREE of the following are valid sources to configure GRUB?

Which TWO of the following are valid methods to configure network interfaces on a Linux system? (Choose two.)

A Linux system fails to boot with the error 'Kernel panic: VFS: Unable to mount root fs on unknown-block(0,0)'. After investigation, the administrator suspects that the root filesystem device is not being detected. Which of the following is the most likely cause?

Which THREE steps are required to configure a static IP address on a modern Linux system using systemd-networkd?

Based on the exhibit, which of the following is true about the cleanup.sh job?

A system administrator notices that the /tmp directory is filling up quickly, causing applications to fail. The administrator wants to ensure that files in /tmp are automatically cleaned after a certain period. Which of the following is the best approach without installing additional software?

Which command displays all error messages from the systemd journal since the last boot?

You are a junior administrator for a company that uses a standard disk image for all Linux servers. The image is based on CentOS 7. You need to ensure that new servers automatically install all available security updates during the first boot. You plan to run a command in a startup script. Which command should you use?

Which command lists all installed packages on a Debian-based system by querying the dpkg database?

A systems administrator downloads a .deb package file but it fails to install due to unmet dependencies. Which command sequence should be used to resolve the dependencies and complete the installation?

Which three files are essential for network configuration and name resolution on a typical Linux system? (Choose three.)

Refer to the exhibit. The system administrator notices the /var/log partition is nearly full. The syslog file is 2GB. Which command will safely reduce the size of this log file without stopping the logging daemon?

Refer to the exhibit. An application uses this JSON policy to control execution of commands. If a user tries to run /usr/bin/passwd, what will happen?

During boot, a Linux system displays 'Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. Which of the following is the most likely cause?

An administrator wants to run a shell script every day at 2:00 AM. Which command should be used to edit the user's personal crontab?

Which file is used by GRUB to load the kernel at boot time?

An administrator added a new APT repository to sources.list. Which command must be run to make the system aware of the packages from that repository?

Refer to the exhibit. Which file has a special permission that allows a user to execute the file with the privileges of the file owner?

An administrator needs to copy a directory hierarchy from one server to another over SSH, preserving permissions, ownership, and timestamps. Which command is most appropriate?

To prevent the 'nouveau' kernel module from loading at boot, which configuration file should be edited?

Which TWO commands can be used to display the current firewall rules in a system using nftables? (Choose two.)

Arrange the steps to schedule a cron job that runs a script every day at 2 AM.

A Linux administrator manages a server that runs a custom application requiring a specific kernel module to be loaded at boot. The server uses SysV init and has the module listed in /etc/modules. However, after a recent kernel update, the module fails to load automatically at boot. The administrator can manually load the module with 'modprobe <module>' after the system is running. The application depends on this module being loaded before any network services start. Which of the following actions should the administrator take to ensure the module loads automatically at the correct time during boot?

Match each package manager to its associated distribution family.

Which directory under the root filesystem is defined by FHS as containing variable data that may change in size, such as logs and spools?

An administrator is configuring a new server with two SATA disks. The first disk (/dev/sda) holds the root filesystem. The second disk (/dev/sdb) is intended to provide additional storage for user home directories. The administrator partitions /dev/sdb using 'fdisk' to create a single partition /dev/sdb1, formats it with 'mkfs.ext4' and adds the following line to /etc/fstab: '/dev/sdb1 /home ext4 defaults 0 2'. After rebooting, the /home directory is empty and the command 'df -h' does not show /dev/sdb1. However, running 'mount /dev/sdb1 /home' manually works perfectly. The disk is not listed in 'cat /proc/mounts' before the manual mount. What is the most likely cause of this issue?

You are the system administrator of a small office network. The company has a Debian-based server that runs a critical database application. The database package was installed from the official Debian repository. After an ‘apt upgrade’, the database service fails to start. The error log indicates a library version mismatch. You suspect the upgrade updated a shared library that the database depends on, but the database binary was not updated because the repository no longer supports it. The vendor provides a custom .deb package for the database on their website. You need to restore the database functionality as quickly as possible, but you also want to avoid breaking other packages that may depend on the newer library. What should you do?

A system administrator writes a script that extracts data from a CSV file and inserts it into a database. The script works correctly when run manually but fails when executed by cron. Which environment variable is most likely causing the issue?

An administrator wants to allow user 'john' to run all commands as root without a password. Which sudoers entry accomplishes this?

An administrator notices the system clock is drifting. Which command can be used to enable automatic time synchronization using NTP on a system with systemd?

Which THREE files are used by CUPS to manage printer queues? (Choose THREE.)

A web server running Apache on Linux is experiencing slow response times. The administrator runs 'netstat -tuln' and sees many connections in TIME_WAIT state. Which of the following is the best course of action to improve performance?

A developer needs to ensure a bash script exits immediately if any command fails, and also prints each command before executing it. Which set of shell options should be used at the beginning of the script?

Which THREE directories under the root filesystem are typically used for variable data that changes frequently during system operation, according to FHS?

Which THREE locations are used to configure package repositories on a typical Linux system? (Choose three.)

A system is not logging messages to /var/log/syslog. Which command should an administrator use first to diagnose the issue?

Which TWO files are used to configure kernel boot parameters in GRUB?

A Linux system has two network interfaces: eth0 and eth1. The administrator wants to bond them for increased throughput. Which kernel module is required for bonding?

Which THREE commands are used to manage systemd services? (Choose THREE.)

A system administrator is troubleshooting a package dependency issue on a Debian system. Which three commands can be used to display dependency information for a package? (Choose three.)

Which THREE are valid fields in a GRUB 2 configuration file (grub.cfg) generated by update-grub? (Choose three.)

Arrange the steps to troubleshoot a service that fails to start.

Which TWO of the following commands can be used to list all installed packages on a Debian-based system?

Based on the exhibit, what does the 'rc' status for the package 'apache2-bin' indicate?

The system administrator wants to use the entire sdb disk as a single partition. Which command will partition sdb with a single partition occupying the whole disk?

An administrator ran 'dnf update' and a critical application broke. The administrator wants to undo the last transaction and return to previous state. Which command should be used?

Refer to the exhibit. The administrator is unable to SSH into the server (TCP port 22) from a remote host. The iptables rules are as shown. What is the most likely cause?

According to the Filesystem Hierarchy Standard (FHS), which TWO directories are intended for variable data that persists across system reboots? (Choose two.)

According to the Filesystem Hierarchy Standard (FHS), which directory contains essential system binaries required during boot?

An administrator needs to find all files in the /var/log directory that have been modified in the last 24 hours. Which command should be used?

Which TWO commands can be used to display the current runlevel of a SysV init system?

Which TWO commands can be used to view all running processes on a Linux system? (Choose TWO.)

An administrator wants to add a kernel parameter 'quiet splash' to the default boot entry. Which file should be edited?

Refer to the exhibit. The root filesystem is at 95% capacity. Which option will free space on the root filesystem?

A system administrator notices that a server with an ext4 filesystem fails to boot after editing /etc/fstab. The error message indicates that the root filesystem cannot be mounted. Which of the following is the most likely cause?

An admin needs to create a new filesystem on /dev/sdc1 with a 256-byte inode size and a 1:512 block to inode ratio for a mail server expected to store millions of small files. Which mkfs command best meets these requirements?

Arrange the steps to configure a static IP address on a Linux system using the command line.

Which TWO tools can be used to query DNS records? (Choose two.)

The system administrator wants to add a new swap partition on /dev/sdb2. After creating the partition, which command should be used to initialize it as swap?

During system startup, GRUB 2 displays a prompt. Which command should be typed at the GRUB prompt to boot the currently selected entry normally?

A user reports that a cron job is not executing. The cron job is defined in /etc/crontab. The administrator checks the system logs and finds no errors. Which command should the administrator use to verify that the cron daemon is running?

Which two commands can be used to send a test email from the command line to verify SMTP functionality? (Choose two.)

Which sed command will replace the first occurrence of 'foo' with 'bar' on each line of a file?

An administrator wants to list all lines in a log file that do NOT contain the word 'ERROR'. Which command should be used?

A user reports that running '/usr/local/bin/myapp' from the command line results in 'bash: /usr/local/bin/myapp: No such file or directory'. The exhibit shows the file exists and is a valid executable. What is the most likely cause of the error?

A Linux system's hostname resolution does not consult /etc/hosts before querying DNS. Which file controls the order of name resolution services?

An administrator needs to check the system's load averages without displaying any process information. Which command should be used?

A systems administrator maintains a Linux web server running Apache HTTP Server (version 2.4) with three virtual hosts. The server logs are stored in /var/log/httpd/ and are rotated using logrotate, which is configured with the default settings that came with the Apache package. The administrator has noticed that after the nightly log rotation, the main access log file (access_log) is empty, while the rotated log files (e.g., access_log.1, access_log.2) contain the previous day's data. Furthermore, new HTTP requests are being logged into the most recent rotated file (access_log.1) instead of the current access_log file. The administrator has verified that the logrotate cron job runs successfully, and that the log files are owned by the root user with read/write permissions for the root group. No errors appear in the system logs. The Apache service continues to run and serve web pages. Which of the following actions should the administrator take to ensure that Apache writes new log entries to the current access_log file after rotation?

You are a system administrator for a small company running a web server on Ubuntu 20.04 LTS. The web server application was installed using apt from the official repositories. Recently, a critical security patch was released for the web server package. You run 'apt update' and 'apt upgrade' but the package is not upgraded. You check the package status with 'apt-cache policy <package>' and see that the installed version is 2.4.41-4ubuntu3.6, and the candidate version is the same. The latest patched version in the repository is 2.4.41-4ubuntu3.7. You verify that the system has internet connectivity and that the repository URLs in /etc/apt/sources.list are correct. What is the most likely reason the upgrade is not being offered?

A technician is troubleshooting a system that fails to boot with the error 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. What is the most likely cause?

Refer to the exhibit. A user runs 'python --version' and gets 'Python 3.9.1'. Which command would run Python 2 instead?

A company's server administrator needs to replace an existing DNS server (192.168.1.10) with a new one (192.168.1.20). Which file must be updated on all DHCP clients to ensure they use the new DNS server?

Which TWO commands are used to install packages on a Debian-based system? (Choose two.)

A directory contains files with spaces and special characters in their names. An administrator wants to delete all files older than 30 days using find and xargs. Which command is safe?

A Linux system has a 500GB SSD. The administrator wants to partition it to support a web server with the following requirements: root (/) 20GB, swap 4GB, /var 50GB, /home 100GB, and the remaining for /srv. Which partitioning strategy is best practice according to the FHS and performance considerations?

An administrator reviews the above DHCP server logs. Based on the output, which statement is correct about the DHCP transaction?

Refer to the exhibit. A system administrator runs 'ip route show default' and gets this output. What does it indicate?

A Linux administrator is troubleshooting a package dependency issue. When attempting to install package 'foo', the package manager reports a missing dependency 'libbar.so.2'. Which of the following is the most appropriate next step?

An administrator wants to prevent a specific user, 'john', from being able to schedule cron jobs. Which file should the administrator modify?

Which directory contains information about hardware devices in a hierarchical structure, such as PCI devices and USB devices?

Which TWO of the following are true about the 'source' command in bash?

A mail server using Postfix is rejecting emails from a partner domain. The administrator checks the maillog and sees 'relay access denied'. Which Postfix configuration parameter is most likely misconfigured?

Which TWO of the following are true about the /proc filesystem?

The administrator wants the sshd service to start automatically at boot. Which command should be used?

A system administrator needs to check if a filesystem has any errors without actually performing a repair. Which command should be used?

Which command can be used to check whether a specific kernel module is currently loaded?

Which THREE steps are required to configure a network interface with a static IP address using the ip command (assuming interface eth0)? (Choose three.)

Which TWO commands can display the UUID of block devices?

A medium-sized company runs a web server on Linux with two 1TB disks in a software RAID1 (mdadm) configuration for the root filesystem and /var. Recently, the /var partition is reporting low disk space. The administrator discovers that old log files are consuming space but should be rotated. However, the logrotate service is not running. After starting logrotate, it fails to rotate some logs because of missing directories. Additionally, the administrator wants to add a third disk (500GB SSD) for additional storage and mount it under /srv/webdata. The disk is new and not partitioned. The server uses systemd and the current /etc/fstab uses UUIDs. What is the correct sequence of steps to add the new disk and ensure it is mounted automatically at boot?

An administrator runs the command 'find / -name "*.conf" 2>/dev/null | head -n 10' and notices that the command returns very quickly. Which statement best describes what happened?

A server runs systemd-resolved and uses a VPN. DNS queries fail intermittently. The administrator checks /etc/resolv.conf and finds it is a symlink to /run/systemd/resolve/stub-resolv.conf. Which command should be used to view the effective DNS servers and debug the issue?

You work for a hosting company that manages hundreds of CentOS 7 servers. Each server runs a standard set of monitoring tools. Your team needs to deploy a custom monitoring agent that is only available as source code (tarball). The agent must be installed on all servers from a central repository. You have set up an internal YUM repository with the compiled RPMs of the agent. On a test server, you run 'yum install custom-agent', but it fails with a message that the package is not found. You verify the package is present in the repository directory and that the createrepo command has been run. Which step is most likely missing?

Which command displays information about currently loaded kernel modules?

Which of the following directories is NOT defined in the Filesystem Hierarchy Standard (FHS)?

Refer to the exhibit. The /var partition is nearly full. Which of the following is the most appropriate first step to free up space?

Refer to the exhibit. The system has a single disk with three partitions. Which partition contains the root filesystem?

An administrator is migrating a legacy service from a SysV init system to a systemd unit. The service is a long-running daemon that forks once. The admin writes a unit file of Type=forking, sets PIDFile correctly, and enables the service. On the next reboot, the service starts but systemd reports that the service entered 'failed' state shortly after start, even though the process is running. The log shows: 'PID file /var/run/myservice.pid not readable (yet?) after start.' What is the most likely cause? Options: A) The service does not write its PID file quickly enough, B) The PIDFile path is wrong, C) The unit file should use Type=simple instead, D) The service needs a TimeoutStartSec increase.

Refer to the exhibit. What can be concluded about the cron daemon based on this systemctl output?

Which TWO of the following are valid ways to capture the output of a command into a variable in Bash?

Which directory contains the kernel modules for the currently running kernel?

A system administrator needs to ensure a custom script runs every time the system boots. Where should the script be placed for execution during the boot process on a standard Linux system?

An administrator needs to ensure that a specific kernel module is loaded automatically at boot. Which file should be used to permanently load the module?

A technician needs to output only the kernel release number. Which command should be used?

A user can successfully ping a web server but cannot access the website via a browser. Which is the most likely cause?

A system administrator notices that the system's syslog messages are not being written to /var/log/messages. The rsyslog service is running. The administrator wants to check the configuration syntax of rsyslog. Which command should be used?

A server with a udev rule fails to consistently assign a persistent network interface name. What is the most likely cause?

Refer to the exhibit. A user tries to write to /mnt/usb/myfile.txt as a non-root user and receives a permission denied error. What is the most likely reason?

An administrator needs to identify the device file for the first SATA SSD in a server. Which device file should they use?

Which THREE directories are commonly used for mounting removable media in Linux?

A system administrator is responsible for a production Debian 10 (buster) server that hosts a critical web application. The application requires the package 'libssl1.1' version 1.1.1 or higher, but the official Debian 10 repository only provides version 1.1.0. The administrator has already attempted to install the newer version from Debian 11 (bullseye) sources, but this caused dependency conflicts with the existing libc6 version. The server cannot be upgraded to Debian 11 due to application compatibility. The administrator needs to resolve this situation without breaking the existing system or introducing unofficial packages. Which of the following is the most appropriate course of action?

A Linux administrator is managing a server that uses RPM-based package management. They need to find which installed package provides the '/etc/ssh/sshd_config' file. Which command should they use?

A system administrator notices that the system clock is consistently 5 minutes ahead of the actual time. The NTP service is enabled and running. Which command should the administrator run to force an immediate time synchronization?

Which TWO commands can be used to view the contents of a compressed file named archive.tar.gz without extracting it to disk?

A script uses 'set -e' and then executes 'grep pattern file'. If the pattern is not found, the script exits. Which of the following modifications would prevent the script from exiting while still allowing detection of the pattern's absence?

After running 'ip route show default', a system administrator sees no output. Users on that system can only communicate with hosts on the local subnet. What is the most likely cause?

Which file defines the APT software repositories used by a Debian-based system?

An administrator runs 'lsmod' and sees a module with a usage count of 1. What does this indicate?

A system administrator wants to list all files in a directory that have been modified in the last 24 hours. Which command would be most appropriate?

Which THREE conditions will cause the fsck command to automatically run on the root filesystem during boot? (Choose three.)

A script running as a daemon should perform clean-up operations when it receives SIGTERM. Which command inside the script sets up this behavior?

A server has a partition /dev/sda2 that is almost full. The admin suspects a large file has been deleted but is still held open by a process. Which command can identify such a file?

A Linux system has a software RAID1 array /dev/md0 consisting of /dev/sda1 and /dev/sdb1. After replacing a failed disk, the administrator runs 'mdadm --manage /dev/md0 --add /dev/sdc1', but the array remains degraded. Which command should be used to check the status of the array?

Given a file with lines like 'John:23:Engineer', which awk command prints only the name and department (first and third fields) separated by a space?

Which THREE package management tools are native to Debian-based Linux distributions? (Choose exactly three.)

You are a junior system administrator tasked with adding a new 500GB HDD to a Debian 11 server that will be used for backup storage. The server currently has a 120GB SSD with two partitions: sda1 (boot) and sda2 (root). You have physically installed the HDD and it is recognized as /dev/sdb. You need to partition the disk with a single partition covering the entire disk, format it as ext4, and ensure it is automatically mounted at /backup at boot time. Which sequence of commands should you execute to accomplish this?

Which THREE of the following are valid systemd targets?

During boot, the kernel must mount the root filesystem. Which of the following is responsible for providing the kernel with the location of the root filesystem?

A system administrator needs to ensure that a bash script continues executing even if any command in the script fails. Which of the following should be used at the beginning of the script?

A Red Hat system administrator suspects that the files belonging to the 'openssh-server' package have been modified since installation. Which command verifies the integrity of the installed package files?

The /proc filesystem is described as a virtual filesystem. Which statement best describes its purpose?

A technician is troubleshooting network connectivity. The server's IP is 192.168.1.10/24, and the gateway is 192.168.1.1. The server can ping the gateway but cannot ping 8.8.8.8. Which command is most appropriate to check if the default route is configured?

A system administrator notices that the NTP service on a Linux server is not synchronizing time with external NTP servers. The administrator runs 'ntpq -p' and sees that all servers listed have a 'reach' value of 0. Which of the following is the most likely cause?

A Linux administrator wants to update the local package index from all configured repositories on an Ubuntu system. Which command accomplishes this?

Refer to the exhibit. The administrator expects logs to be sent to a remote syslog server at 192.168.1.100 on UDP port 514. However, no logs are being received at the remote server. Which is the most likely issue?

Which THREE commands can be used to display the UUID of a filesystem on a Linux system without superuser privileges? (Choose three.)

A system administrator needs to install a package 'foo' which depends on library 'libbar.so.2' that is not currently installed. The administrator runs `apt-get install foo` and receives an error about unmet dependencies. Which of the following is the most appropriate next step?

On a Linux server using systemd and Postfix for email service, an administrator needs to diagnose a delivery failure for a local user. Which command should be used to view the most recent mail-related system journal entries?

Which TWO commands can be used to obtain information about the CPU architecture of a Linux system?

Which TWO commands can be used to display the contents of a compressed file without decompressing it to disk? (Choose two.)

Refer to the exhibit. An administrator runs 'ntpq -p' and sees the output shown. What is the most likely cause of the '16' stratum and '0.000' delay/offset?

Refer to the exhibit. What will be the output when this script is executed?

A script produces both standard output and error messages. An administrator wants to save the output to 'out.log' and the error messages to 'err.log', but also wants to see both on the terminal. Which command achieves this?

After creating a new user with 'useradd john', the user 'john' cannot log in. What is the most likely cause?

Which TWO options in /etc/fstab affect whether a filesystem is mounted at boot? (Choose two.)

A disk is partitioned with GPT. The administrator wants to see the partition type GUIDs and partition UUIDs. Which command is most appropriate?

A Linux system fails to boot with the error 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. Which of the following is the most likely cause?

A system administrator wants to ensure that the filesystem on /dev/sdb1 is checked for errors every 30 mounts. Which command accomplishes this?

Which TWO of the following commands can be used to create a new filesystem on a partition?

A Linux system has two SATA disks: /dev/sda (250GB) and /dev/sdb (500GB). The administrator wants to create a logical volume group named 'vgdata' using partitions on both disks, then create a 600GB logical volume named 'lvdata' for a database. Which sequence of commands should be used?

A systemd service unit file must be configured to automatically restart the service if it exits unexpectedly. Which directive should be used?

Which THREE of the following statements are true about the /etc/shadow file?

A system has multiple CPUs but only one is being used. Which file under /sys/ can be checked to verify CPU online status?

A shell script uses the variable expansion ${var:-default} to set a default value for an environment variable. The script prints unexpected output when the variable is set to an empty string. Which expansion should be used to ensure the default is only used when the variable is unset, not when it is empty?

A system administrator needs to install the latest version of a package named 'webapp' from a third-party repository that has been added to the system. Which command should be used to update the package list and install the package in one step?

Which THREE signals are commonly used to terminate a process with the kill command?

Refer to the exhibit. An administrator attempts to remount /mnt as read-only but receives the error shown. What is the most likely cause?

A system administrator needs to create a new Logical Volume (LV) in an existing LVM setup. Which sequence of commands is correct?

You are a Linux administrator for a large e-commerce company. The company's application server runs Ubuntu 22.04 and uses a Btrfs filesystem for the /srv/app partition to take advantage of snapshots and compression. During a routine maintenance window, you create a snapshot of the /srv/app subvolume using 'btrfs subvolume snapshot /srv/app /srv/app_snapshot'. Later, you need to roll back to the snapshot because of a failed application update. You attempt to delete the original subvolume with 'btrfs subvolume delete /srv/app', but the command fails with the error: 'ERROR: cannot delete '/srv/app': Device or resource busy'. You check that no processes are using the directory with lsof, and it shows no open files. The /srv/app subvolume is the default subvolume and is mounted via fstab with the option 'subvol=/' (the root of the Btrfs filesystem). What is the most likely reason for the deletion failure, and how should you proceed?

A Linux technician receives a report that a USB flash drive inserted into a system is not automatically detected. Which command should the technician use to verify if the device is recognized by the kernel?

When troubleshooting a problem with a Debian package installation, an administrator wants to see which version of a package would be installed from the configured repositories. Which command displays the candidate version?

A Yellowdog Updater Modified (YUM) transaction that included several package installations and upgrades completed successfully, but a recent change caused a service to break. The administrator wants to revert the entire transaction using its transaction ID. Which command should be used?

Which TWO commands can be used to display information about block devices such as disks and partitions? (Choose exactly two.)

A system administrator needs to schedule a recurring maintenance task that runs every Monday at 3 AM. Which crontab entry is correct?

A zombie process appears in the process list. The parent process has PID 1234. Which command will most likely remove the zombie?

Refer to the exhibit. The system administrator wants to ensure the /data filesystem is mounted only if it is available at boot time, and if not, the system should continue to boot without error. Which change should be made to the /etc/fstab entry for /data?

Refer to the exhibit. A system administrator notices that remote SSH connections are being blocked from all IP addresses except 10.0.0.5. Which configuration change would allow SSH from any IP?

A systems administrator is responsible for a Linux server that runs a custom application. The application writes logs to /var/log/app.log and rotates them using logrotate. Recently, the server ran out of disk space because log files were not being rotated. The administrator checks the logrotate configuration file /etc/logrotate.d/app and finds: /var/log/app.log { weekly rotate 4 compress missingok notifempty } The administrator manually runs 'logrotate -f /etc/logrotate.d/app' and the log rotates successfully. However, the next day, the log is not rotated again. The administrator checks the cron job for logrotate and finds that /etc/cron.daily/logrotate exists and runs logrotate /etc/logrotate.conf. The administrator checks /etc/logrotate.conf and sees that it includes /etc/logrotate.d/*. What is the most likely reason the log is not rotating automatically?

According to FHS, which directory should NOT be mounted on a networked filesystem (e.g., NFS) because it contains host-specific configuration files?

Refer to the exhibit. A Linux system fails to boot with a kernel panic. The dmesg output shows the disk is detected and partitions are recognized. Which of the following is the most likely cause of the kernel panic?

Based on the dpkg -l output in the exhibit, what does the 'rc' status indicate for the apache2 package?

Match each Linux command to its primary function.

An ext4 filesystem is experiencing performance degradation due to very frequent small writes. Which tune2fs option can help by reserving a percentage of blocks for the root user to prevent fragmentation?

Refer to the exhibit. What is the file permission in numeric mode for /etc/crontab?

A system has multiple APT repositories configured. The administrator needs to ensure that for a specific package, the version from a particular repository is always preferred over others, regardless of version number. Which configuration would achieve this?

A script uses a here-document to pass multi-line input to a command. Which here-document syntax will prevent variable expansion inside the document?

Refer to the exhibit. The 'mount -a' command fails for the NFS mount. What is the most likely cause?

A system administrator wants to ensure that the syslog service starts automatically on boot and is running immediately without a reboot. Which command sequence should be used?

Refer to the exhibit. What will be the default permissions of a newly created file using the touch command?

A system administrator needs to perform incremental backups of a large directory /data. The backup strategy requires a full backup every Sunday and incremental backups on weekdays. Which tar command satisfies this requirement using the --listed-incremental option?

An administrator needs to downgrade a package from version 2.0 to version 1.9. Which apt-get command can be used to perform this action?

A small business runs a web application on a Linux server that uses Apache to serve dynamic content via PHP-FPM. The server currently uses the default Apache configuration, but the administrator wants to improve security by limiting access to the server's administrative interface (located at /admin) to only the local network (192.168.1.0/24). The administrative interface is accessed via a separate VirtualHost on port 443. The administrator has created a new VirtualHost configuration file for the admin site. However, after reloading Apache, users from outside the local network can still access the /admin page. The administrator has verified that the VirtualHost is being parsed and that mod_authz_core is enabled. Which of the following actions would most likely resolve the issue?

Which THREE statements are true about the sed command?

A system administrator is configuring a Linux server to act as a router. The server has two network interfaces: eth0 (192.168.1.1/24) and eth1 (10.0.0.1/24). Which of the following commands enables IP forwarding on this server?

An administrator is troubleshooting a DNS issue. The command 'dig @8.8.8.8 example.com' returns a response, but 'host example.com' returns 'Host not found'. Which of the following is the most likely cause?

Based on the exhibit, what will happen if the syslog service is stopped?

A Linux server running multiple virtual hosts on Apache suddenly becomes unresponsive to web requests. The administrator finds that the server still responds to ping. Which diagnostic command would best identify whether Apache is accepting connections?

An administrator needs to install apache2 version 2.4.41-4ubuntu3.4 from the security repository to ensure the latest security patches. Based on the exhibit, which command should they use?

A Linux system fails to boot after installing a new kernel. Which step should be taken first to recover the system?

A technician is tasked with installing a package from a third-party repository on a CentOS 7 system. What is the correct first step to add the repository?

Which THREE of the following are valid symbolic mode expressions for the chmod command?

Refer to the exhibit. An administrator installed a new command in /opt/bin/ but cannot run it without specifying the full path. What is the likely cause?

Refer to the exhibit. Based on the apt-cache showpkg output, which version of vim would be installed if the administrator runs 'apt-get install vim' without specifying a version?

A web server runs Apache and generates extensive access logs. To conserve disk space, an administrator sets up a cron job that runs nightly at 2:00 AM. The job executes a shell script located at /usr/local/bin/rotate_logs.sh. The script is intended to find all .log files in /var/log/apache2/ that are older than 7 days, compress them with gzip, and move the compressed files to /var/log/archive/. However, after several days, the administrator notices that the /var/log partition is nearly full and the logs are not being compressed. The cron log shows the job ran at the scheduled time but produced no terminal output (stdout or stderr). The script itself contains no explicit echo statements or error handling. The administrator has root access and wants to diagnose the problem without disrupting the running web server. Which of the following is the most appropriate first step to identify the failure?

You are a Linux administrator for a company that runs a web server on a system with limited disk space. The web server logs are stored in /var/log/httpd/access_log and grow quickly. The operations team requires that the most recent logs be available for troubleshooting, but logs older than 7 days must be compressed to save space. You decide to implement log rotation using logrotate. The logrotate configuration file for httpd currently contains: /var/log/httpd/*.log { daily rotate 7 compress delaycompress missingok notifempty sharedscripts postrotate /bin/systemctl reload httpd 2>/dev/null || true endscript } After applying this configuration, you notice that log files are being compressed immediately instead of after one rotation. What is the most likely cause and the correct step to fix this?

What is stored in the first sector of a hard disk (Master Boot Record)?

On a Fedora system, which command is used to update all installed packages to their latest versions?

You are the system administrator for a small business running a Red Hat Enterprise Linux 8 server that hosts a MySQL database and a web server. The server has two physical disks: a 240GB SSD (sda) with partitions sda1 (boot), sda2 (root), sda3 (swap), and a 1TB HDD (sdb) with a single partition sdb1 mounted at /var/lib/mysql. The server has been running for months without issues. However, this morning you receive alerts that the MySQL database is not accepting new connections. You log in and find that the /var filesystem is 100% full. You check the disk usage and see that /var/lib/mysql uses 90% of the space, but there are also large log files in /var/log/httpd. To free up space immediately and restore database service while planning a permanent solution, you decide to compress old log files and move some database archives to a backup server. After compressing several log files with gzip, the available space increases by only a few MB. You then delete some old database backups from /var/lib/mysql/backup, but the space usage shown by df remains unchanged. What is the most likely cause of this behavior?

Refer to the exhibit. A system administrator finds this line in /etc/rsyslog.conf. What is the effect of this configuration?

A script needs to remove all trailing whitespace (spaces and tabs) from each line of a file. Which sed command will accomplish this?

Refer to the exhibit. An administrator runs this command expecting to capture both stdout and stderr into output.txt. However, the file contains only stdout. What is the error?

A system takes a long time to boot due to a service that fails to start. Which systemd command can be used to identify the service causing the delay?

An administrator runs `fsck /dev/sdb1` on an ext4 filesystem that is currently mounted. What is the likely outcome?

Which of the following commands will display the default gateway of a Linux system?

An application assumes its data is stored in /opt/app/data, but the /opt filesystem is running out of space. The administrator moves the data to /var/app/data. Which method will allow the application to continue accessing the data at /opt/app/data without modifying the application's configuration?

A developer downloads the source code for a kernel module and attempts to compile it using `make`. The compilation fails with an error indicating that the kernel header files are missing. Which package should be installed to provide the necessary headers on a Debian system?

Refer to the exhibit. The administrator restarts the sshd service. What is the new main PID after restart?

Which TWO of the following are valid mount options for the ext4 filesystem?

After plugging in a USB storage device, the system does not automatically mount it. The 'lsusb' command shows the device. What is the first command to check if the kernel detected the block device?

An organization's DNS server (BIND) is authoritatively serving the example.com zone. The administrator needs to add a mail exchange record for mail.example.com with priority 10. Which resource record should be added to the zone file?

Refer to the exhibit. A user 'user1' tries to run the setuid binary 'myapp' but gets permission denied. What is the most likely reason?

Refer to the exhibit. Based on the dpkg output, what is the status of the 'ftp' package?

A company is setting up a database server that requires high reliability and support for snapshots. The storage will be on a single large disk. Which filesystem is best suited for this requirement?

A system administrator wants to compile and install a program from source. After running './configure --prefix=/opt/myapp', the configure script fails with an error about missing 'libssl-dev'. What should the administrator do to resolve this issue?

Which TWO commands can be used to create an ext4 filesystem on a partition?

Which TWO commands are commonly used to start, stop, or restart system services on a Linux system that uses systemd as its init system?

An administrator wants to remove a package 'apache2' but keep its configuration files on the system. Which command should be used?

Which command creates an ext4 filesystem on /dev/sdb1 without interactive prompts?

A company runs a critical web application on a Linux server (Ubuntu 20.04) with Apache and MySQL. The server has two network interfaces: eth0 (public IP) and eth1 (private IP). Recently, the application has been experiencing intermittent connectivity issues. Users report that the web page sometimes loads slowly or times out. The administrator checks the network configuration and finds the following: eth0 is configured with a static IP 203.0.113.10/24, gateway 203.0.113.1; eth1 is configured with a static IP 10.0.0.10/24, no gateway. The administrator runs 'ip route show' and sees: default via 203.0.113.1 dev eth0, 10.0.0.0/24 dev eth1 proto kernel scope link src 10.0.0.10 metric 100. The administrator also notices that the system's /etc/resolv.conf contains nameserver 8.8.8.8 and nameserver 8.8.4.4. The MySQL server is configured to listen on 127.0.0.1. What is the most likely cause of the intermittent connectivity issues?

An administrator needs to find files that have been modified within the last 24 hours. Which two parameters are valid for the find command to accomplish this? (Choose TWO)

Which THREE directories are required by the Filesystem Hierarchy Standard (FHS) to exist on the root filesystem? (Choose three.)

In a bash script, a variable 'file' is set to '/var/log/syslog'. Which expansion will yield the string '/var/log'?

A sysadmin is troubleshooting a connectivity issue between two servers in different subnets. The output of 'traceroute 192.168.2.10' shows packets reaching a router but not the destination. The router's firewall uses iptables. Which rule would prevent the traceroute from completing?

Which TWO configuration files are commonly associated with NTP client configuration?

Refer to the exhibit. After adding a new disk to the system, the device /dev/sdb appears. However, the administrator cannot create partitions on /dev/sdb using fdisk. What is the most likely reason?

Refer to the exhibit. The root filesystem is nearly full. The administrator needs to increase its size. Which steps should be performed?

Which command displays information about the CPU, including model name, cache size, and flags?

A Linux system with a custom kernel fails to boot after a new kernel is compiled and installed. The boot process stops at a prompt: 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. The root filesystem is on /dev/sda2 with ext4. The system has an initramfs generated with dracut. The admin can boot from a previous kernel. Which is the most appropriate next step to troubleshoot and fix the issue? Options: A) Rebuild the initramfs using 'dracut --force --kver' with the correct kernel version, B) Add 'root=/dev/sda2' to the kernel command line, C) Use 'mkinitrd' with the '--preload' option for ext4 module, D) Run 'ldd /sbin/init' to check for missing libraries.

Refer to the exhibit. The system fails to boot with an error 'UUID=e5f6g7h8 not found'. Which is the most likely cause?

A company runs a critical database server on Linux. The server has a hardware RAID controller with two logical volumes: one for the operating system (LV1) and one for the database data (LV2). The server uses LVM on top of the RAID volumes. Recently, the database performance has degraded. The administrator suspects that the file system on LV2 is heavily fragmented. The server uses the ext4 filesystem. The administrator wants to check the fragmentation level and, if necessary, defragment the filesystem without unmounting it or causing downtime. What should the administrator do to minimize fragmentation impact while maintaining availability?

Which THREE of the following filesystem types are journaling filesystems? (Choose exactly three.)

Which THREE of the following are valid methods to install a package from a local .deb file?

An openSUSE administrator needs to add a new repository from a URL and refresh the package cache. Which command sequence accomplishes this?

Refer to the exhibit. The system logs show the above messages. What is the most likely cause and the correct first action?

Which TWO commands can be used to display network interface statistics on a Linux system?

A system administrator is responsible for a Linux server running a critical application. The server recently experienced an unplanned power outage. Upon rebooting, the system fails to reach the default target and drops into an emergency shell. The administrator notices that the root filesystem (/) is mounted read-only. The /etc/fstab file contains the following lines: UUID=abc123 / ext4 errors=remount-ro 0 1 UUID=def456 /home ext4 defaults 0 2 UUID=ghi789 none swap sw 0 0 The administrator suspects that the /home filesystem has a corrupt superblock and is causing the boot failure. The administrator needs to check and repair the /home filesystem without causing data loss. Which of the following is the correct course of action?

Which TWO of the following are required for a system to boot using UEFI?

Match each Linux signal to its default action.

Refer to the exhibit. An administrator needs to edit /etc/example.conf to change setting1 to 'production' and add a new line 'setting2=value' after the include line. The file must be edited in place without creating a backup. Which command sequence achieves this?

Refer to the exhibit. On boot, which filesystem will be checked first by fsck?

An administrator wants to change the owner of all files in /data to user 'web' without changing the group. Which command should be used?

Refer to the exhibit. Which users are allowed to use the 'at' command?

After modifying /etc/fstab, an administrator wants to test if the new mount points can be mounted without rebooting. Which command should be used?

A host on the 192.168.1.0/24 network cannot reach the internet. Based on the exhibit, which is the most likely cause?

Which TWO directories are commonly used to store source code before compiling? (Choose two.)

A junior system administrator, Sarah, has written a shell script to automate a backup process on a Linux server. The script is located at /home/sarah/backup.sh and has execute permissions. The script contains the line 'mybackup /home/data'. The 'mybackup' command is installed in /usr/local/bin and works correctly when Sarah runs it from her interactive shell. However, when she runs the script using './backup.sh', it fails with the error 'line 5: mybackup: command not found'. Sarah has verified that /usr/local/bin is in her PATH by executing 'echo $PATH' in an interactive session. Which of the following is the most likely cause of this issue?

Which TWO commands can be used to display the UUID of a filesystem? (Choose two.)

Which command returns the directory part of a full path like '/home/user/script.sh'?

A user 'jdoe' already exists. The administrator needs to add 'jdoe' to the 'staff' and 'admin' groups without changing other group memberships. Which command accomplishes this?

Which TWO statements about GRUB 2 are correct?

The system is unable to mount a filesystem that should be identified by UUID 1234-5678. The administrator checks /etc/fstab and finds the entry: UUID=1234-5678 /data ext4 defaults 0 2. What is the most likely cause of the mount failure?

Refer to the exhibit. The administrator wants to mount /dev/sdb1 persistently using its UUID. Which line should be added to /etc/fstab?

An admin runs 'lsblk' and sees that /dev/nvme0n1p1 is listed with size 512M and mounted at /boot/efi. What is the most likely filesystem type?

Which TWO of the following commands output the total number of lines in a file?

A user needs to schedule a backup script to run every weekday at 2:00 AM. Which command should they use to set up this recurring job?

After running 'df -h', the administrator sees that /dev/sda1 is 100% used. 'du -sh /mountpoint' shows only 50% used. What is the most likely cause?

Which THREE of the following directories are defined in the Filesystem Hierarchy Standard (FHS) and are expected to exist on a typical Linux system?

Which THREE of the following are valid systemd service unit types?

An administrator needs to downgrade a package 'apache2' to a specific older version using APT. Which TWO commands can achieve this? (Choose exactly two.)

After a failed package upgrade, a Debian system shows 'unmet dependencies' when trying to install any new software. What is the most appropriate command to fix this condition?

Arrange the steps to create a LVM logical volume and mount it.

Refer to the exhibit. The remount command fails. What is the most likely cause?

Refer to the exhibit. How many physical disks are present in the system?

To enable disk quotas for user quotas on a filesystem, which line should be added to /etc/fstab's mount options?

A small office has a network printer with IP 192.168.1.100. The printer is shared via CUPS. A user reports that they cannot print a document from their workstation. The printer appears in the list of available printers, but when they try to print, the job hangs in the queue with status 'processing'. The administrator suspects the printer may be offline or the CUPS service is not running. Which command should the administrator run first to gather diagnostic information about the printer and its queue?

Which TWO characteristics describe the difference between 'apt-get' and 'aptitude'? (Choose two.)

Which THREE steps are necessary to configure a static IP address using ifcfg files on a RHEL-based system? (Choose THREE.)

A server in a corporate network uses systemd-resolved for DNS. Internal hostnames (e.g., server.example.lan) fail to resolve, but external names (e.g., google.com) work. The /etc/resolv.conf is a symlink to /run/systemd/resolve/stub-resolv.conf. The administrator checks the systemd-resolved configuration and finds that the internal DNS server is listed globally, but the network interface has no specific DNS set. Which command should be used to assign the internal DNS server to the interface and fix resolution?

Which three commands are commonly used to display information about running processes?

Order the steps to mount an NFS share from a remote server.

A user submitted a print job to a CUPS printer but used the wrong options. Which command should the administrator use to cancel the job?

A developer wants to change the ownership of all files in a directory tree to the user 'www-data' and group 'www-data', but only files that are currently owned by user 'nobody'. Which command accomplishes this?

Which systemd target corresponds to the traditional runlevel 3?

A system administrator wants to disable the graphical target and boot to the text mode multi-user.target permanently. Which command should they run?

A Linux system fails to boot with the error: 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. What is the most likely cause?

Which TWO commands can be used to sort the output of ps -ef by the resident set size (RSS) in descending order?

An administrator needs to display the current and previous runlevels of a Linux system. Which command provides this information?

Refer to the exhibit. Based on the mount options shown, which filesystem is most likely to store filenames with mixed case and support long filenames?

Match each Linux directory to its standard purpose.

A system has a software RAID1 array (/dev/md0) with two disks: /dev/sda and /dev/sdb. Disk /dev/sda fails. Which command sequence will replace the failed disk with a new /dev/sdc without stopping the array?

A system administrator needs to install a new kernel on a Debian-based system. Which TWO commands can be used to achieve this? (Choose TWO.)

A system administrator needs to ensure that the httpd service starts automatically when the system enters the multi-user.target. Which command should be used?

Based on the /etc/fstab entry, which filesystem will be checked by fsck at boot time?

Refer to the exhibit. Which of the following is true about SSH access to this server?

A sysadmin notices that after modifying iptables rules, the SSH service is unreachable from a specific subnet (192.168.1.0/24). Which command should be used to view the current rules with line numbers for easier identification?

Which THREE of the following directories are part of the FHS and must be present on a standard Linux system? (Choose three.)

An organization wants to implement a centralized logging solution for multiple Linux servers. Which service should run on the central server to receive syslog messages?

An administrator needs to mount a USB drive with the ext4 filesystem automatically at boot. The drive has a filesystem label 'DATA'. Which entry in /etc/fstab will mount it at /mnt/data with noatime and default mount options?

A web server running on this host is not accessible from clients. Based on the exhibit, what is the most likely reason?

A system administrator notices that the server's clock is consistently off by several minutes. Which service should be used to synchronize the time with an external time source?

Which TWO of the following are required for a bash script to be executed by the shell (assuming the script is in the current directory)?

Which TWO of the following are valid methods to change the default runlevel on a SysV init-based system?

Refer to the exhibit. What is the current state of the SSH service?

Match each ACL term to its meaning.

A user reports that they cannot connect to a remote server using SSH. The administrator checks the SSH server status and it is running. Which of the following is the most likely cause?

A sysadmin wants to prevent an APT package from being upgraded automatically but still allow it to be upgraded manually if needed. Which configuration method best achieves this?

Refer to the exhibit. The system administrator sees that /var/log is 93% full and the syslog file is nearly 2 GB. What is the most appropriate immediate action to free up disk space without losing any critical log data?

An administrator needs to mount an ISO file located at /tmp/data.iso to /mnt/iso for read-only access. Which command should be used?

To add a kernel parameter temporarily to the kernel command line at boot, what key should be pressed in the GRUB menu?

Which command schedules a job to run once at 2:30 PM today?

A dependency analysis shows that removing package 'libfoo' will also remove 'appA' and 'appB' because they depend on libfoo. The administrator wants to remove libfoo but keep appA and appB. What is the best approach?

Which TWO of the following are Debian package management tools?

A user reports that a file cannot be saved due to 'No space left on device'. Which command should the administrator use to verify disk usage?

Based on the exhibit, the 'custom' repository shows 0 packages. What is the most likely cause?

A user downloaded a Debian package file named 'software.deb'. Which command should be used to install it?

Refer to the exhibit. An administrator is trying to install Google Chrome but receives a GPG error. Which command should be run to add the repository's GPG key?

A Debian system has a broken package that was partially installed. Which command will attempt to fix dependencies and configure all unpacked but not configured packages?

A developer is troubleshooting a shell script that uses the variable $HOME but it outputs nothing when the script runs. The script is executed with ./script.sh from an interactive shell. What is the most likely cause?

A user reports that they cannot access the company's web server. The administrator confirms the server is running and network connectivity is fine. Which command should be used to verify that the HTTP service is listening on the correct port?

A user frequently runs 'ls -la' and wants to create an alias 'll' for this command. Which command adds this alias persistently?

A system administrator needs to see the boot messages recorded by systemd-journald from the current boot. Which command is most appropriate?

Refer to the exhibit. During the next boot, which filesystem will be checked first by fsck?

Refer to the exhibit. The job runs every hour but the administrator notices that it does not execute on Sundays. Which cron syntax element is responsible?

A user reports that when they run 'ls -l' in their home directory, they see files but all files have permissions like '-rwxrwxrwx', which is unexpected. The system administrator checks and finds that the user's umask is set to 000. The user wants all new files to be created with default permissions of -rw-r--r-- (644) and directories that are drwxr-xr-x (755). What should the user set their umask to?

A system administrator wants to monitor network traffic on a specific port (TCP/443) entering the server. Which command will capture packets on interface eth0 and display them in real-time?

A user reports that their cron jobs are not executing. The user has a valid crontab file and can execute the commands manually. Which of the following is the most likely cause of this issue?

A company runs a web server on Linux with two hard disks: /dev/sda (500GB) and /dev/sdb (500GB). The root filesystem is on /dev/sda1, and /var is on /dev/sda2. The administrator wants to add a new disk /dev/sdc (500GB) to be used as additional storage for /var/www/html. The new disk should be configured as an LVM physical volume and added to an existing volume group named 'vg_web'. The volume group currently has 200GB free space from /dev/sdb1. The administrator intends to extend the logical volume 'lv_web' mounted at /var/www/html by 300GB. Which of the following is the correct sequence of commands to achieve this without data loss?

Which three actions can an administrator take to securely erase data on a disk before decommissioning?

During boot, a server loads the wrong kernel. Which file should the administrator modify to change the default kernel in a standard GRUB 2 configuration?

A junior system administrator is tasked with setting up a new Linux server that will act as a network time client. The server must synchronize its clock with the external NTP pool servers 0.pool.ntp.org, 1.pool.ntp.org, and 2.pool.ntp.org. The administrator installs the ntp package and edits /etc/ntp.conf to include the following lines: server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org However, after restarting the ntpd service, the administrator notices that the system time does not appear to be synchronized. The command 'ntpq -p' returns no output. The administrator checks the status of the ntpd service with 'systemctl status ntp' and sees that the service is active (running). What is the most likely reason for the synchronization failure?

An administrator needs to mount an ISO image file /tmp/image.iso to the directory /mnt/iso. Which command should be used?

Which command combination will display a sorted list of unique lines from a file?

An administrator is configuring a DHCP server to assign IP addresses to clients in the 192.168.10.0/24 subnet. The server should provide the default gateway as 192.168.10.1 and DNS server as 8.8.8.8. Which option in /etc/dhcp/dhcpd.conf defines the default gateway?

Which command is used to view the last few lines of a log file and simultaneously follow new entries as they are written?

Refer to the exhibit. This line is from /etc/passwd. What does the third field (1001) represent?

Arrange the steps to configure a firewall rule using iptables to allow SSH.

Refer to the exhibit. What is the purpose of the 'test -x /usr/sbin/anacron' command in the cron entries?

During boot, a sysadmin sees the message 'Buffer I/O error on device sda1, logical block 0'. What does this most likely indicate?

An administrator needs to replace all occurrences of 'old_host' with 'new_host' in the file /etc/hosts. Which sed command should be used?

Which TWO statements about udev rules are correct? (Choose two.)

Refer to the exhibit. What is the expected outcome of the kill command?

A system administrator notices that a server with a freshly installed Linux system fails to boot with the error 'No bootable device found'. The server has a single SATA hard disk connected to the motherboard's SATA controller. Which of the following is the most likely cause of this issue?

An administrator wants to combine two network interfaces into a single logical interface for redundancy and increased throughput. The system uses NetworkManager. Which method is currently recommended to achieve this?

Which THREE of the following are characteristics of UEFI firmware compared to legacy BIOS? (Select exactly 3.)

Which of the following commands displays the amount of free disk space on all mounted filesystems in a human-readable format?

An administrator notices that /var/log/syslog is 3 GB in size, despite logrotate being configured to rotate logs weekly and keep 4 weeks. The logrotate configuration file /etc/logrotate.d/syslog contains: /var/log/syslog { weekly rotate 4 compress missingok notifempty } The administrator checks that logrotate is scheduled via cron and sees that the cron job exists. However, the administrator suspects that logrotate might not have been running. Which of the following commands should the administrator run first to force log rotation and diagnose the issue?

Match each file system type to its typical description.

During the boot process, the system stops at a GRUB prompt. Which command should be typed to continue booting?

A medium-sized company runs a web application on a Linux server. The server uses systemd and has the following configuration: the web application service (webapp.service) is configured to start after network.target and requires a database service (database.service) to be running. The database service has a Restart=on-failure directive. Recently, the server experienced a power outage. Upon reboot, the system administrator notices that the web application fails to start because the database service is in a failed state. The administrator checks the status of database.service and sees 'inactive (dead)' with no recent attempts to restart. The journal shows that the database service failed to start because a required filesystem (mounted at /var/lib/database) was not mounted when the database service tried to start. The filesystem is listed in /etc/fstab with the nofail option. The administrator wants to ensure that in future reboots, the database service starts successfully and the web application comes up without manual intervention. Which of the following is the best course of action?

Refer to the exhibit. An administrator wants to verify the integrity of the kernel-core package by checking its signature. Which command is used?

Refer to the exhibit. What type of traffic is being captured?

An administrator plans to back up the /home filesystem using dump. Which option to dump is required to perform a full backup?

Refer to the exhibit. Which statement is true about SSH root login on this server?

A script contains the following line: for i in $(cat file.txt); do echo $i; done. The file file.txt contains a single line with multiple words. How many times will the loop execute?

A system administrator notices that the system time is slowly drifting from the actual time. The system uses chrony for NTP synchronization. The administrator runs 'chronyc sources' and sees no reachable sources. The firewall is enabled and configured. Which action should the administrator take to resolve the time synchronization issue?

A company runs a legacy application on a Linux server. The application fails to start after a reboot, claiming a 'cannot open shared object file' error. The system administrator checks the library path and finds that the required library is present in /usr/local/lib but the application cannot find it. The administrator has verified that the library file exists and is readable. Which of the following is the most likely cause and solution?

Which TWO commands can be used to display the amount of free and used memory on a Linux system? (Select exactly 2.)

Which TWO of the following commands can be used to replace text patterns in a file and output the result?

A small business uses a Linux server running CUPS to share a network printer. For several months, all employees could print successfully. Today, an employee in a different subnet reports that printing does not work. The administrator checks the server: cupsd is running, the printer is configured with an IPP URI pointing to the printer's IP address, and the printer is idle. The administrator can ping the printer from the server. The administrator checks the CUPS error log and sees the following line multiple times: 'E [04/Oct/2024:10:15:22 -0400] [Client 5] client-error-not-authorized'. Which of the following actions should the administrator take to resolve the issue?

Refer to the exhibit. Why does the cron job fail?

A server with UEFI firmware and GPT partitioning has a corrupted bootloader. Which command can be used to reinstall GRUB in UEFI mode?

Which TWO commands can be used to schedule a one-time task at a specific time in the future? (Choose TWO.)

Which TWO conditions would cause the boot process to fall back to the GRUB rescue shell? (Choose two.)

A user compiling software from source successfully runs './configure' and 'make', but the resulting binaries are not in the PATH. Which command should be run to install them system-wide?

A small business runs a Linux server hosting a web application and a PostgreSQL database. The server uses LVM for storage, with a single volume group vg_data containing two logical volumes: lv_web (50GB) and lv_db (100GB). The root filesystem is on a separate disk. The administrator receives alerts that the database volume is at 95% capacity. The server has additional unused space from a recently added disk that was added to the volume group as an additional physical volume, but the space has not been allocated. The administrator runs 'vgs' which shows VG vg_data with total size 500GB, allocated 150GB, and free 350GB. The administrator wants to increase the size of lv_db by 50GB. Which course of action should the administrator take?

Which THREE of the following are valid files or directories used by the Domain Name System (DNS) resolution process on a Linux system?

An administrator wants to enforce a password history that prevents using the last 5 passwords. Which directive should be added to /etc/pam.d/system-auth?

An administrator needs to restart the SSH service after a configuration change. Which TWO commands can accomplish this on a systemd-based system?

A systems administrator needs to find all files in /var/log that were modified in the last 24 hours and contain the word 'error'. Which command accomplishes this?

A sysadmin is tasked with configuring the shell environment for all users. Which three files are typically sourced by Bash during login? (Choose THREE)

A system administrator wants to configure NTP client on a server running systemd and using systemd-timesyncd. Which file should be edited to set the NTP server?

Refer to the exhibit. How many SATA controllers are detected, and what is the connection speed of the SSD?

A technician is repairing a system and needs to mount the root filesystem from a different disk to /mnt/sysroot. The partition is /dev/sda2 with an ext4 filesystem. Which command should be used?

An administrator wants to prevent a specific package from being upgraded during routine system updates. Which command marks the package as held back?

Refer to the exhibit. A new installation requires the root filesystem to be placed on LVM. Based on the current disk layout, which partition is most suitable for use as an LVM physical volume?

A helpdesk technician receives a call about a user who is unable to run a script that was working yesterday. The user says they only changed the ownership of a file in their home directory. The script is located in /usr/local/bin and is owned by root:root. The script has permissions 755. Which of the following is the most likely cause of the issue?

A system administrator installs a new RPM package, but it fails due to a missing library dependency. Which command can best identify the specific dependency that is missing?

Refer to the exhibit. A system administrator checks the integrity of the passwd package on a CentOS 7 system using rpm -V. Based on the output, what is the most likely cause of the 'missing' line?

A system administrator wants to mount a USB flash drive formatted with the ext4 filesystem. The device is detected as /dev/sdc1. Which command should be used to mount the device to /mnt/usb?

A user reports that a USB drive (device /dev/sdc1) is not automatically mounted at boot. The output of 'blkid' and the relevant line in /etc/fstab are shown in the exhibit. What is the most likely cause of the failure?

Which THREE of the following commands can be used to transform delimited text (e.g., CSV) by selecting specific fields or columns?

In the /etc/shadow file, a user's password hash begins with '$6$'. What hash algorithm does this prefix indicate?

An administrator suspects that a critical system file has been modified after installation. Which command can be used to verify the integrity of all installed RPM packages on a RHEL system?

A system administrator is tasked with migrating several shell scripts from a legacy UNIX system to a new Linux server. One script uses the command 'grep -E "pattern1|pattern2"' which works fine on the old system. However, on the new Linux server, the patterns are not being matched correctly. The administrator suspects it is due to differences in grep implementations. Which of the following is the most likely reason for the discrepancy?

Which THREE of the following are types of expansion performed by the bash shell during command parsing?

A system administrator wants to install custom scripts that should be available to all users. The scripts are not part of any package and should be placed under the Filesystem Hierarchy Standard (FHS). Which directory is most appropriate?

Which TWO commands can be used to count the number of lines in a file named 'data.txt'?

Refer to the exhibit. An administrator wants to mount /dev/sda4 persistently by its UUID. Which line should be added to /etc/fstab?

After updating the SSH configuration, a sysadmin restarts the sshd service, but remote connections still use the old settings. Which command should be used to reload the configuration without dropping existing connections?

A company wants to migrate a database server from ext4 to XFS to support larger files and better scalability. The current data resides on a single partition /dev/sda1 mounted at /data. Which procedure ensures a successful migration with minimal downtime?

A company security policy requires that user accounts be disabled after 90 days of inactivity. The system administrator locks user accounts using 'usermod -L username'. However, users with SSH key authentication can still log in. The administrator has verified that the locked flag is set in /etc/shadow. Which of the following is the most likely explanation?

An administrator needs to create a new ext4 filesystem on /dev/sdb1 and wants to reserve 2% of the blocks for the root user. Which command should be used?

After a system crash, the root filesystem (ext4) is mounted read-only and the administrator needs to perform an interactive check. Which command should be used?

Which THREE of the following are valid systemd targets?

Which TWO of the following are valid methods to reduce boot time on a Linux system? (Select exactly 2.)

A Linux system fails to boot after an admin added an entry in /etc/fstab to mount an NFS share. The error message indicates 'mount: can't find /mnt/nfs in /etc/fstab'. Which is the most likely cause?

A system boots in UEFI mode, and the administrator wants to add a new kernel entry to the EFI boot manager. Which tool should be used?

A security administrator needs to allow SSH access from the 10.0.0.0/8 network but deny all other traffic to port 22. The firewall uses iptables with default policy ACCEPT on the INPUT chain. Which set of rules should be added?

A system administrator suspects a failing power supply because the server randomly reboots. Which command can be used to check hardware health and event logs?

Which TWO of the following are valid methods to list currently loaded kernel modules?

A system administrator wants to schedule a script to run every Monday at 3:00 AM, but only if the system clock is set to local time (not UTC). Which crontab entry should be used?

A server has two disk drives: /dev/sda (SSD) and /dev/sdb (HDD). The administrator wants to place frequently accessed files on the SSD for performance. Which approach best achieves this using Linux filesystem features?

You are a systems administrator for a medium-sized company that runs a web server on a Linux host. The server has two physical disks: /dev/sda (250 GB) and /dev/sdb (500 GB). The root filesystem is on /dev/sda2, and /var is on /dev/sda3 (50 GB). The web application stores user-uploaded files in /var/www/uploads, which is part of the /var filesystem. Recently, /var has been running out of space because uploads have grown to 40 GB. You have added /dev/sdb1 (500 GB) and created an ext4 filesystem on it. You need to make the space available for uploads without disrupting the current file paths. The server must remain online during the process. Which of the following actions should you take?

Which command displays the system's architecture (e.g., x86_64)?

A data center server with two NICs (eth0 and eth1) is configured for network bonding in mode 1 (active-backup). The admin notices that after a cable pull on eth0, the bond interface fails over to eth1 as expected. However, when the cable is reconnected to eth0, the bond remains on eth1 indefinitely. The admin checks /proc/net/bonding/bond0 and sees that eth0 is marked as 'up' but not as 'active'. Which parameter is most likely missing from the bond configuration? Options: A) 'miimon=100' to enable link monitoring, B) 'downdelay=0', C) 'updelay=0', D) 'primary=eth0' to prefer eth0 as the active slave.

Refer to the exhibit. How much unpartitioned space is available on /dev/sda?

A system administrator wants to ensure a service named 'app.service' starts automatically on boot in a systemd-based system. Which command should be used?

Refer to the exhibit. What is the current default target?

A system administrator notices that the system boots to the graphical interface but wants to change it to boot to a non-graphical multi-user target. Which command will make this change persistent?

An administrator wants to change the ownership of a file to user 'jane' and group 'staff'. Which command should be used?

A system administrator needs to locate the largest directories under /var to free up disk space. Which command is most appropriate?

Order the steps to create and apply a file system permission using ACLs.

A company is deploying a new web application and needs to ensure high availability. They have two web servers and want to use DNS round-robin. Which DNS record type is most appropriate?

Which shell loop is most appropriate for iterating over all files in a directory, performing an action only on regular files, while safely handling filenames with spaces?

Refer to the exhibit. When will the cron job execute?

Which command adds a new group named 'developers' to the system?

A system reports 'No space left on device' but 'df -h' shows only 60% usage. Which command would help identify the cause?

A system administrator is troubleshooting a server where the /var partition is full, causing services to fail. The administrator deletes old log files in /var/log, but the available space does not increase. Which step should be taken next?

An administrator needs to extend a logical volume by 10GB. The volume group has available physical extents. Which command should be used?

An administrator notices that a large file on an ext4 filesystem is taking up more disk space than expected based on its size. Which command would show the actual disk usage (block allocation) of the file?

A database server on a Linux system is configured to listen on TCP port 3306. The administrator wants to restrict access to the database server to only the local network (192.168.1.0/24) using iptables. Which of the following iptables rules achieves this?