scenario questions

An administrator wants to ensure that a service starts automatically after a system crash. Which systemd command should be used?

A security policy requires that a user's password must expire 90 days after last change, and the user must change it immediately on next login. The last password change was 30 days ago. Which set of commands achieves this?

A developer reports that a custom daemon fails to start after a reboot. The daemon's unit file is located in /etc/systemd/system/custom.service. Which of the following is the most likely cause?

A financial firm requires all internal SSH connections to be encrypted with at least 256-bit ciphers. An administrator is configuring the SSH server. Which configuration line should be added to /etc/ssh/sshd_config?

A storage administrator wants to create a software RAID 10 (1+0) array using six disks. Which mdadm command is appropriate?

A system administrator needs to ensure that the 'nginx' service starts automatically after a reboot on a system using systemd. The service unit file exists and is currently disabled. Which command should be used?

An administrator needs to combine two sorted text files, /tmp/a.txt and /tmp/b.txt, into a single sorted stream on standard output while also removing duplicate lines that appear in both files. Which command should be used?

A Linux server uses a software RAID1 array /dev/md0 assembled from /dev/sdb1 and /dev/sdc1. The administrator wants to replace the failing disk /dev/sdc with a new disk /dev/sdd without losing data or interrupting service. Which two steps are required to correctly replace the disk in the array? (Choose two.)

A security policy requires that user 'svc_backup' have a password that never expires. Additionally, the account should be locked after 90 days of inactivity. Which set of commands achieves this?

A Linux administrator needs to ensure that the nginx.service is restarted automatically if it crashes, but only after a 10-second delay, and that it does not restart more than 5 times within 1 minute to avoid a restart loop. Which set of directives in the [Service] section achieves this?

A custom systemd service unit file has been created but the service fails to start with 'Exec format error'. What is the most likely cause?

After editing a service unit file, which command must be run for changes to take effect?

Which TWO of the following are correct statements about systemd journald configuration?

Which THREE commands can be used to list all users currently logged into the system?

A user wants to find all files in /var/log that have been modified within the last 2 days. Which command should they use?

Which THREE of the following statements about Linux file permissions are correct?

A DevOps engineer wants to list all running processes sorted by memory usage in descending order. Which command should be used?

An administrator manages a server whose /home directory resides on the logical volume /dev/vg_users/lv_home. Usage reports show the LV is 98% full, and the volume group vg_users has 40 GB of free extents. The filesystem is ext4. Which sequence correctly expands the usable space to /home?

Which THREE of the following commands can be used to view the contents of a compressed file named 'file.gz' without permanently decompressing it? (Choose exactly three.)

A Linux server has two interfaces, ens5 (203.0.113.10/24) and ens6 (10.20.0.0/24 gateway for internal clients). Internal clients must reach the internet through ens5. The administrator has enabled net.ipv4.ip_forward=1 and configured NAT on ens5, but clients still cannot reach external hosts. Which two additional checks are most likely to resolve the problem? (Choose two.)

Which THREE commands can display the current CPU utilization statistics on a Linux system?

An e-commerce company runs a critical application on a Linux server that occasionally becomes unresponsive. The server has 64GB RAM and runs a Java application. The operations team notices that during peak hours, the system becomes very slow and eventually the application crashes with 'OutOfMemoryError'. After restart, it works fine for a while. They suspect a memory leak but also want to ensure the system does not go down during peak hours. The system uses systemd to manage the Java service. The administrator needs to implement a solution that: (1) automatically restarts the service if it becomes unresponsive, (2) limits the memory usage of the service to prevent OOM kills on the system, and (3) provides early warning of high memory usage. Which of the following approaches best meets these requirements?

An administrator is configuring a new server with two 1 TiB NVMe disks, /dev/nvme0n1 and /dev/nvme1n1, and wants to use LVM to create a single logical volume that spans both disks for a database. The volume group will be named vg_db and the logical volume lv_db. Which two commands are required to initialize the disks for LVM and create the volume group? (Choose two.)

You are a senior Linux administrator for a large data center. A junior admin reports that a newly deployed application server (192.168.100.50/24, default gateway 192.168.100.1) cannot communicate with a legacy server (192.168.200.50/24, default gateway 192.168.200.1). The two subnets are connected via a router (192.168.100.1 and 192.168.200.1). From the app server, you can ping the legacy server's IP successfully. However, when you try to establish an SSH session from the app server to the legacy server, it times out. You check the legacy server's firewall (ufw) and find that it allows SSH (port 22) from the entire 192.168.0.0/16 range. You also confirm that the SSH daemon is running and listening on 0.0.0.0:22. What is the most likely cause?

An administrator is configuring a Linux server as a router. The server has two interfaces: eth0 (192.168.10.1/24) connected to the internal LAN and eth1 (203.0.113.2/24) connected to the internet. After enabling IP forwarding, internal clients still cannot reach external websites. Which command is required to allow the internal subnet to be translated to the external interface?

A storage administrator must add a persistent secondary IPv4 address 192.0.2.50/24 to interface eth1 on a RHEL 9 server using NetworkManager. The primary address is already configured. Which command adds the address so that it survives a reboot?

A system administrator is setting up a high-availability cluster using shared storage. Which filesystem is best suited for this environment where multiple nodes need simultaneous read-write access to the same filesystem?

A system administrator needs to permanently configure a network interface named ens33 with a static IPv4 address of 192.168.1.100/24 and a default gateway of 192.168.1.1 on a system using NetworkManager. Which command should the administrator use to achieve this?

Which TWO commands can display the current environment variables?

An administrator must ensure that a Linux router forwards IPv4 packets between its two interfaces, eth0 and eth1, without rebooting. Which command enables this behavior immediately?

A system administrator needs to ensure the Apache httpd service starts automatically on system boot. Which command should they use?

Which TWO of the following are valid ways to mount a filesystem with the 'noexec' option to prevent execution of binaries?

Based on the journalctl output, what is the most likely cause of the service failure?

Refer to the exhibit. The output of 'ps aux' shows a process named 'process_hog' with PID 1234 consuming 99.5% CPU. The process is stuck in an infinite loop and does not respond to SIGTERM. Which signal should be used to forcefully terminate it?

You are managing a Linux server that hosts a critical web application. The server is running low on disk space in the root filesystem, and you need to free up space urgently. You run 'df -h' and see that /dev/sda1 is mounted on / and is 95% full. You also notice that /var/log/messages is over 2 GB in size. The application writes logs to /var/log/app.log, which is also large. The server has a separate /var partition that has plenty of free space. The application must continue running with minimal downtime. You need to compress and rotate logs without losing any data, and ensure that the root filesystem has at least 10% free space. Which of the following actions should you take first to achieve this goal?

A system administrator needs to change the ownership of the file /var/www/html/index.html from user alice to user bob, and also change the group to webdev. Which command should they use?

Based on the exhibit, what is the most likely cause of the blocked task?

A system administrator needs to configure a new systemd service unit file for a custom application. The service should start after the network is fully online and requires the /opt/data directory to be mounted. Which section of the unit file should contain the After= and Requires= directives to define these dependencies?

A systemd-networkd managed interface enp1s0 needs to be configured with a static IP address 192.168.1.100/24 and a default gateway via 192.168.1.1. Which .network file configuration is correct?

A system administrator is setting up a new backup server. The server has two 4TB disks /dev/sda and /dev/sdb. The administrator decides to create a RAID1 array and then an LVM volume group on top of the RAID device. After creating the RAID1 array /dev/md0, they create a physical volume, volume group named vg_backup, and a logical volume lv_data of size 2TB. Then they format with ext4 and mount at /backup. During testing, they realize that the backup data volume will likely exceed 2TB eventually. They want to expand the filesystem to use all available space in the RAID array. What is the correct procedure?

You are a systems administrator for a company that runs a critical application on a Linux server with two network interfaces: eth0 (public IP 203.0.113.10/24, gateway 203.0.113.1) and eth1 (private IP 10.0.1.10/24, no gateway). The server must be accessible via SSH (port 22) from the internet, but only from a specific management subnet 198.51.100.0/24. Additionally, the server should be able to access the internet for package updates, but no other inbound traffic from the internet is allowed. The local firewall is iptables. After implementing rules, you find that the server cannot reach the internet (e.g., ping 8.8.8.8 fails), but SSH from the management subnet works. What is the most likely cause?

A user 'alice' cannot log in via SSH. The administrator checks /etc/passwd and sees: alice:x:1002:1002::/home/alice:/sbin/nologin. Which command should be used to allow alice to log in with a bash shell?

A system administrator notices that a web server process (PID 1234) is consuming excessive CPU. They want to trace its system calls to identify the cause. Which command should be used?

An administrator needs to temporarily assign the IPv4 address 172.16.5.20/24 to interface ens3, which is currently up but unconfigured. The change should not persist across reboots. Which command accomplishes this?

Order the steps to recover a forgotten root password on a Linux system using single-user mode.

A cron job runs a script every hour but sometimes fails because the script cannot find commands like 'tar' and 'gzip'. The script works when run manually from a terminal. What is the best fix?

A Linux administrator is configuring a systemd service unit for a database application. The administrator needs to ensure that the service is automatically restarted if it crashes, but only after a 10-second delay, and that the restart is not attempted if the service is explicitly stopped by an administrator. Which two directives should be used in the [Service] section to achieve these requirements? (Choose two.)

A technician must verify which network services are listening on TCP ports and which processes own them on a production server. Which command provides this information directly?

An administrator is diagnosing disk space and wants to see the total size of the /var/log directory and all its contents in human-readable units, without listing every individual file. Which command provides exactly this summary?

An administrator is troubleshooting name resolution on a server. Queries for internal names succeed, but every query for external names fails with 'connection timed out; no servers could be reached'. The file /etc/resolv.conf contains 'nameserver 10.20.30.40' and 'nameserver 10.20.30.41'. The internal DNS servers are reachable, and the administrator wants to test which external name servers actually respond. Which command best performs this test?

A system administrator wants to kill a process with PID 1234 that is not responding to SIGTERM. Which command will forcefully terminate it?

An administrator deploys a new custom service using a unit file called myapp.service. The service needs to start automatically at system boot. Which command should the administrator run to achieve this?

An administrator has added a new disk (/dev/sdb) to a Linux system. The disk is to be used as a physical volume in an existing volume group 'vg_data'. Which sequence of commands should be executed to make the disk available to the volume group?

A Linux server has two network interfaces: eth0 (192.168.1.10/24) and eth1 (10.0.0.10/24). The administrator wants to configure the server to route traffic between the two networks. Which two actions are required? (Choose two.)

A user wants to continuously monitor a log file that is being written to by a running service. Which command achieves this?

Based on the exhibit, which process will be affected if the root user runs 'kill 5678'?

An administrator needs to check the UUID of a filesystem on /dev/sdb1. Which command should be used?

A user 'dba' tries to login via SSH and fails. Based on the exhibit, what is the most likely cause?

A Linux administrator is managing a systemd service called app.service that runs a Java application. The service is configured with Restart=on-failure and RestartSec=5. After a recent update, the application crashes immediately upon start with exit code 1. The administrator notices that systemd keeps restarting the service every 5 seconds indefinitely. Which command should the administrator use to view the number of times the service has been restarted and the current restart limit status?

The command 'ss -tuln' shows port 80 is listening on a server, but a remote client cannot connect via HTTP. What is the most likely cause?

A file server has an XFS filesystem on /dev/vg_data/lv_share that is nearly full. The volume group has 50 GB of free space. The administrator runs lvextend -L +20G /dev/vg_data/lv_share, which succeeds. However, df -h still reports the original size. What should the administrator do next to make the additional space usable?

A service is configured to run as a specific user. Which directive in the [Service] section sets the user?

A service named webserver.service is failing to start. The administrator wants to see the most recent error messages related to this service. Which command provides this information?

Match each file system type to its typical use case.

A DevOps engineer wants to measure how long a specific command takes to execute. Which command should be used?

Which command will display all groups a specific user belongs to, including both primary and supplementary groups?

A junior administrator is troubleshooting a server and needs to inspect the manual page for the 'ip' command, but the system is a minimal install where the man pages for that package were not installed. The administrator still wants the short one-line usage summary for 'ip' printed directly to the terminal. Which command should they run?

Refer to the exhibit. The administrator receives alerts that the root filesystem is almost full. Which command could free up space by removing old log files?

A system administrator needs to create a hard link named /home/user/report_hardlink to an existing file /data/reports/report.txt. Which command should be used?

A system with systemd experiences a service that fails to start due to a 'Failed to start' error with status 203/EXEC. What is the most likely cause?

An administrator needs to configure software RAID 5 on three disks /dev/sda, /dev/sdb, /dev/sdc with a spare disk /dev/sdd. Which command correctly creates the RAID array?

Match each Linux permission type to its symbolic representation.

A junior administrator needs to check the current runlevel and then change the system to runlevel 3 (multi-user, no GUI) on a SysVinit-based system. Which command sequence will accomplish this?

A Linux administrator is troubleshooting a custom systemd service named data-sync.service that repeatedly fails with the error 'start request repeated too quickly'. The unit file has Restart=always and RestartSec=5. Which command should the administrator use to reset the failed state and clear the restart counter so the service can be started again?

A system administrator needs to ensure that a Linux server can communicate with other hosts on the same subnet. Which command should be used to verify the IP address and netmask configuration?

A user wants to set the permissions of a file to 'rwxr-xr--'. Which octal permission value should they use with chmod?

A technician configured a new network interface eth1 on a CentOS 7 server but the interface does not obtain an IPv4 address via DHCP. Which of the following is the most likely cause?

A system administrator needs to identify all available block devices on a Linux server. Which two commands can be used to accomplish this? (Choose two.)

An administrator needs to change the ownership of the directory /srv/www to user webadmin and group webteam, including all existing files and subdirectories. Which command accomplishes this?

A system administrator notices that a new 500GB SSD (/dev/sdb) is not being recognized by the system after installation. The server uses UEFI and GPT partitioning. Which command should the administrator run first to verify that the disk is detected by the kernel?

An administrator wants to change the primary group of user 'jane' from 'staff' to 'developers'. Which command accomplishes this?

Which two commands can add an existing user to a supplementary group?

Which TWO directives are typically used in a systemd service unit file to configure dependencies?

A Linux server is unable to resolve the hostname 'app.internal.example.com' but can resolve other names. The /etc/nsswitch.conf file contains: hosts: files mdns4_minimal [NOTFOUND=return] dns. The /etc/hosts file does not list the hostname. Which configuration change would most likely resolve the issue?

A process is consuming 99% CPU and is unresponsive to normal shutdown requests. After running 'top', you see the PID is 1234. What is the most appropriate command to stop the process gracefully first?

A user needs to locate all regular files under /etc that are larger than 1 MB and have not been accessed in the last 30 days. Which command finds these files?

To display the first 10 lines of a file named 'log.txt', which command is correct?

A system administrator wants to view the last 10 lines of the system log file '/var/log/syslog' and continue to watch for new lines as they are appended. Which command should be used?

A Linux server is configured with a custom systemd service unit for a backup script. After editing /etc/systemd/system/backup.service to add an EnvironmentFile directive, the administrator runs 'systemctl start backup' but systemctl status shows the unit still using the old environment. Which command should the administrator run to apply the unit file changes?

Order the steps to set up passwordless SSH key-based authentication.

A system administrator manages a database server service (database.service) that experiences periodic CPU spikes, causing excessive load on the server. The administrator wants to limit the service's CPU usage to 25% of a single CPU core. The service is running on a system with cgroup v2. Which directive should be added to the [Service] section of the unit file to achieve this?

A process is stuck in an uninterruptible sleep (D state) and cannot be killed. What is the most likely cause?

A system administrator wants to display a list of all currently running processes with their parent process IDs. Which command is most appropriate?

A server has multiple IP aliases on eth0. Remote hosts cannot reach the secondary IP addresses. What should the administrator check?

A user reports that they cannot execute a file even though they are in the file's group. The file has permissions 644 and group ownership 'staff'. The user is a member of 'staff'. What is the likely issue?

A user 'dlee' reports that they cannot run 'sudo' commands despite being in the 'wheel' group. The /etc/sudoers file contains the line '%wheel ALL=(ALL) ALL'. What is the most likely cause?

A Linux server has a filesystem mounted at /data that is running out of space. The administrator needs to identify which directories under /data are consuming the most disk space and then safely remove old log files. Which two commands should the administrator use? (Choose two.)

A server uses firewalld. Which command permanently allows HTTP traffic?

A system has a process stuck in uninterruptible sleep (D state). The administrator wants to identify which kernel function it is waiting on. Which tool should be used?

A large company needs to create 100 user accounts from a list of names in a CSV file. Which tool is most efficient for batch user creation?

A junior administrator needs to mount an ISO image located at /opt/images/install.iso to the directory /mnt/iso without burning it to a physical disc. Which command should be used?

An administrator is preparing a new server that will use software RAID 1 for the root filesystem. The system has two identical 500 GB disks, /dev/sda and /dev/sdb. The administrator wants to create the RAID array and then place LVM on top of it. Which command correctly creates the RAID 1 array using the entire disks?

A system administrator wants to view the current runtime status of the sshd.service, including whether it is active, its main PID, and recent log entries. Which command should they use?

A junior administrator issued the command 'usermod -L alice' to lock the account of user alice. However, alice is still able to log in via SSH using a public key. What is the most likely reason?

Given the routing table, if the server sends a packet to destination 10.0.1.200, which interface will be used and what is the next hop?

A Linux server uses systemd-resolved for DNS resolution. Users report that queries for internal hostnames such as 'db.corp.example.com' are failing, while external names resolve correctly. The administrator runs 'resolvectl status' and sees that the interface eth0 has DNS servers 10.0.0.53 and 'DNS Domain: corp.example.com'. Which command should be used to query the internal DNS server directly and verify that it responds to the name?

A system administrator notices that the disk space on the root filesystem is at 95% usage. After investigating, they find that a large log file named 'access.log' in /var/log is taking up significant space. The administrator deletes the file using 'rm /var/log/access.log' but the disk usage remains at 95%. Running 'df -h' still shows the same usage. What is the most likely cause and the correct next step?

A system administrator cannot restart a service because another unit 'stop' the request. The status message says 'Unit test.service is not running, but has pending stop job'. What is the most likely cause?

Order the steps to set up a LVM logical volume from a new disk.

An administrator has a volume group vg_data with 50 GB of free extents. The logical volume /dev/vg_data/lv_archive is 200 GB and must grow to 350 GB. The administrator runs lvextend -L +150G /dev/vg_data/lv_archive and it fails. Which is the most likely cause?

A system administrator needs to identify the absolute path of the executable that would be run when typing the command 'ls'. Which command should they use?

A junior administrator created a user account with the command `useradd -m devuser`. The account was created without a password, and the administrator now wants to set an initial password so the user can log in. Which command should the administrator use to assign a password to the account?

A system administrator configures a web server using systemd. After creating a custom service unit file, the administrator runs `systemctl daemon-reload` but the service still fails to start with a 'Unit not found' error. What is the most likely cause?

Which THREE of the following are valid systemd unit types?

A Linux server uses LVM for its data volume /dev/vg_data/lv_app. The volume group vg_data has 30 GB of free extents and the logical volume lv_app is currently 100 GB. An administrator runs `lvextend -L +20G /dev/vg_data/lv_app` and receives a success message, but `df -h /app` still reports 100 GB. The filesystem on lv_app is ext4. Which command must the administrator run next to make the additional space usable?

A Linux server cannot reach the internet, but internal LAN connectivity works. The output of 'ip route' shows a default gateway of 192.168.1.1, but pinging 8.8.8.8 fails. What is the most likely cause?

A system administrator is managing a RHEL 8 server that requires a static IP address on interface ens192. The administrator modifies /etc/sysconfig/network-scripts/ifcfg-ens192 to set BOOTPROTO=static, IPADDR=192.168.1.100, PREFIX=24, GATEWAY=192.168.1.1, and DNS1=8.8.8.8. After saving, the administrator runs 'systemctl restart NetworkManager'. The interface obtains the correct static IP and network connectivity works. However, after a reboot of the server, the interface fails to come up with the static IP and instead obtains an IP via DHCP from the local network. The administrator verifies that the DHCP server is active and that the physical connection is good. What is the most likely cause of the issue?

A Linux administrator wants to view the current resource limits (such as CPU and memory) applied to a running systemd service named database.service. Which command will display these limits?

Which bonding mode provides high availability without requiring switch configuration?

A system administrator needs to securely transfer files between two Linux servers using port 22. The administrator uses the following command: 'scp file.txt user@remote:/tmp/'. The transfer fails with the error 'Permission denied (publickey)'. What is the most likely cause?

A company's database server uses LVM for storage. The system administrator notices that the logical volume /dev/vg_db/lv_data is at 95% capacity. The server is in production and cannot be taken offline. The volume group vg_db has free physical extents. Which command sequence should the administrator use to safely increase the size of the logical volume and filesystem without unmounting?

A Linux server is configured to boot into a graphical target, but after a recent kernel update, the system hangs at a black screen after the GRUB menu. You can still access a rescue shell via the installation media. Which command should you use to make the system boot into a multi-user text target by default, allowing you to troubleshoot?

A system administrator wants to combine two network interfaces for increased throughput and fault tolerance. The requirement is that both links are active simultaneously and the system can tolerate a failure of one link without interruption. Which bonding mode should be used?

An administrator configures a systemd service with Restart=on-failure and RestartSec=10. What happens if the service exits with a non-zero exit code?

A system administrator notices that a web server is not reachable from the internet but is reachable from the internal network. The server's IP is 10.0.1.10/24, and the gateway is 10.0.1.1. Which command should be used to verify the default gateway configuration?

A server runs out of inodes. The administrator needs to find which filesystem is exhausted and which directory has the most files. Which command sequence best accomplishes this?

Which command displays the listening UDP ports on a Linux system?

Which THREE statements about Linux network bonding modes are correct? (Choose three.)

Which THREE fields are part of a standard /etc/group entry?

A systems administrator is responsible for a production Linux server running CentOS 7 that provides SSH access to users. The administrator decides to tighten security by restricting SSH access to a specific management subnet 10.0.0.0/24. While connected to the server via SSH from a workstation on 10.0.0.50, the administrator adds the following iptables rule: iptables -A INPUT -p tcp --dport 22 -s 10.0.0.0/24 -j ACCEPT followed by iptables -P INPUT DROP. Immediately after the rule change, the administrator loses all connectivity to the server, including SSH. The administrator suspects that the new default policy dropped the existing SSH session. What is the most reliable method for the administrator to regain access to the server without rebooting?

A Linux administrator needs to configure VLAN tagging on a network bridge to isolate traffic from different virtual machines. The physical interface is eth0, and VLAN ID 100 should be accessible via the bridge br0. Which set of commands correctly creates this configuration using the ip command?

A security policy requires that a user account 'temp_audit' be locked immediately without changing the password. Which command locks the account and prevents login?

An administrator is diagnosing why a server cannot reach the host 198.51.100.25. The server has one interface, eth0, with address 192.0.2.10/24. Running `ip route show` returns only the default route via 192.0.2.1. Which two commands will help determine whether the problem is at layer 2 or layer 3? (Choose two.)

Which command adds an existing user to a supplementary group without removing the user from other groups?

A system administrator is troubleshooting a server that fails to boot because the root filesystem, which is on an LVM logical volume, cannot be found. The administrator suspects that the initramfs does not include the necessary LVM modules. Which command should be used to rebuild the initramfs for the currently running kernel on a Debian-based system?

A user wants to view the contents of a compressed log file /var/log/syslog.2.gz without decompressing it first. Which command should they use?

An administrator created an LVM snapshot of a logical volume to perform a backup. During the backup, the snapshot runs out of space. What will happen to the original logical volume?

An administrator must change the ownership of /srv/project and every file and directory beneath it to user alice and group devs, without altering permissions. Which command should be used?

A system administrator runs 'ss -tuln' and sees that port 80 is listening. What does the 'u' option represent?

Which file stores the encrypted password (or password hash) for user accounts?

Refer to the exhibit. The administrator wants to create a RAID 1 array using /dev/sdb1 and /dev/sdc1. Which command should be used?

You need to check the default gateway on a Linux server. Which command displays the current routing table, including the default route?

Match each Linux package management command to its distribution.

A user reports that they cannot delete a file named 'important.txt' located in their home directory. The file is owned by the user and the user has write permission on the directory. Running 'rm important.txt' produces the error: 'rm: cannot remove 'important.txt': Operation not permitted'. The user has also tried using 'sudo rm' but gets the same error. Which of the following is the most likely cause and correct solution?

A security policy requires that all users in the 'admin' group must have a umask of 027 set automatically upon login. An administrator adds 'umask 027' to /etc/profile. However, users report that the umask is still 022. What is a likely cause?

Order the steps to create a systemd service unit that runs a script at boot.

An administrator receives a report that a specific directory /var/log is consuming too much disk space. Which command should be used to determine the total disk space used by that directory?

A Linux server has a single Ethernet interface eth0. The administrator needs to assign a static IPv4 address 192.0.2.10/24 with gateway 192.0.2.1 on a system that uses systemd-networkd. Which file should be created or edited to configure this interface?

A user reports that a shell script 'backup.sh' in /home/user/scripts fails to execute. What is the most likely cause?

A system administrator receives an alert that disk /dev/sda is predicted to fail soon. The server uses LVM, and /dev/sda is part of a volume group named vg_system. Which of the following is the best course of action to replace the failing disk without downtime?

An administrator needs to delete user 'obsolete' and remove its home directory and mail spool. Which command should be used?

An administrator needs to change the group ownership of the directory /srv/project and all of its existing contents to the group developers, without altering the user ownership. Which command should be used?

Which TWO commands can be used to display the current working directory?

An administrator wants to permanently configure a static IP address on a CentOS 7 system. Which file should be edited?

A technician must create a hard link named 'report_link' to an existing file '/data/report.txt'. Which command should be used?

A Linux administrator needs to modify the default runlevel (target) on a systemd-based Linux server so that it boots into a graphical environment by default. Which command should the administrator use?

A system administrator has a cron job that runs a backup script. The script requires the variable BACKUP_DIR to be set, but the administrator cannot modify the script. Which is the most appropriate place to define the variable for cron?

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

Refer to the exhibit. What is the most likely security issue?

You are a system administrator for a company that runs a web server on a Linux system. The web server logs are stored in /var/log/nginx/access.log. The log file grows rapidly and rotates weekly via logrotate. The system has been running for several months. Recently, the development team reported that the web server is responding slowly. You suspect that the disk I/O might be high due to log file activity. You check the disk usage and find that /var/log/nginx/access.log is 4 GB, and the rotated logs (access.log.1.gz, access.log.2.gz, etc.) total another 10 GB. The /var partition has 20 GB total, so it's 70% full. You decide to reduce the disk usage by compressing the current log file and truncating it without stopping the nginx service. Which command sequence should you use to safely achieve this?

A backup script must create a compressed archive of the /etc directory, preserving file permissions and timestamps. Which command should be used?

A developer reports that a web application's logs are not being written to /var/log/myapp.log. The service runs as user 'myapp' and the log directory /var/log/myapp/ has permissions 755 owned by root. What is the most likely cause?

Which command displays the amount of free and used memory in the system?

Refer to the exhibit. The service unit file has Restart=on-failure, but systemctl show displays Restart=no. What is the most likely reason?

A junior administrator needs to create a new empty file named report.txt in the current working directory. They want to ensure that if the file already exists, its contents are not altered. Which command should they run?

Order the steps to create a new partition on a disk using fdisk.

A network administrator needs to block all incoming SSH traffic (port 22) from the 192.168.2.0/24 subnet. Which iptables command accomplishes this?

An administrator runs `ls -l` and sees a file entry whose permission string begins with a lowercase `l`. What does this indicate about the entry?

An administrator is unable to SSH into the server from a remote host at 192.168.1.100. Based on the exhibited iptables rules, what is the most likely reason?

A user must change their password at next login per security policy. The admin wants to expire the password immediately. Which command accomplishes this?

A system administrator needs to mount an ext4 filesystem with the options 'noatime' and 'errors=remount-ro'. Which mount command is correct?

A junior admin runs 'ls -l' and sees permissions '-rwxrwxr-x' on a file. What is the octal representation?

A system administrator is managing a web application running as a systemd service on a new Linux server. The application requires a specific environment variable, DATABASE_URL, to be set before starting. The administrator has created a custom service unit file at /etc/systemd/system/webapp.service with the following content: [Unit] Description=Web Application Service [Service] ExecStart=/usr/local/bin/webapp Restart=on-failure The administrator prefers to keep configuration separate from the unit file for easier updates. The service fails to start. Upon investigation, the administrator notices that the DATABASE_URL variable is not being passed to the process. What is the most appropriate course of action to ensure the environment variable is correctly set?

A Linux server's boot process fails after a kernel upgrade. The GRUB2 menu appears, but selecting the newest kernel panics. You need to boot the previous kernel temporarily to recover the system. Which command should you use at the GRUB2 menu to edit the selected entry's boot parameters?

An administrator is troubleshooting intermittent connectivity issues. Running 'ping -c 100 -i 0.2 10.0.0.1' shows about 5% packet loss. What is the primary purpose of the '-i 0.2' option?

A service unit has the directive 'ExecStartPre=/bin/true' and 'ExecStart=/usr/bin/myapp'. What is the effect of ExecStartPre?

A Linux server is experiencing performance issues. You need to identify which processes are consuming the most CPU and memory in real-time. Which two commands can provide this information interactively? (Choose two.)

Which TWO commands can be used to display the contents of a text file that has been compressed with gzip without decompressing it to disk?

A Linux server has two interfaces: enp3s0 (192.168.10.5/24) and enp4s0 (10.0.0.5/24). The default route is via 192.168.10.1. A junior admin adds a static route to 10.1.0.0/16 via 10.0.0.1 using the command: ip route add 10.1.0.0/16 via 10.0.0.1. After this, users report that traffic to 10.1.1.0/24 fails. Which command should the administrator run to confirm that the kernel is selecting the correct route and interface for destination 10.1.1.10?

Which TWO methods can be used to set a static IPv4 address on a CentOS 7 system? (Choose two.)

A system administrator is troubleshooting a custom systemd service that fails to start. They want to override a setting in the service's unit file without modifying the original file in /usr/lib/systemd/system/. Which two methods can be used to create a drop-in override? (Choose two.)

Which two commands can be used to set password expiration policies for a user?

A company follows the principle of least privilege. Several developers need sudo access to run specific commands like systemctl and journalctl. What is the best practice for granting this access?

A Linux server's primary interface is ens3. Administrators report that after a recent reboot, the server's hostname resolves to 127.0.1.1 instead of its static address 203.0.113.25. The file /etc/hosts currently contains only the default '127.0.0.1 localhost' line. Which single change will make the hostname resolve to 203.0.113.25 for local lookups while leaving DNS resolution for all other names untouched?

Which THREE are built-in chains in the iptables filter table? (Choose three.)

An administrator wants to force a user to change their password at next login. Which command should be used?

A junior administrator needs to identify the UUID of the ext4 filesystem on /dev/nvme0n1p2 so it can be referenced in /etc/fstab instead of the device path. Which command displays that UUID?

Refer to the exhibit. An administrator tries to start myapp.service with 'systemctl start myapp.service' but receives 'Failed to start myapp.service: Unit myapp.service is not loaded properly: Invalid argument'. What is the most likely issue?

A system administrator needs to ensure that a custom service named 'myapp.service' starts automatically after a reboot and also restarts automatically no matter how the service stops, even if it exits normally. Which two actions should the administrator take? (Choose two.)

After creating an XFS filesystem on /dev/sdb1, an admin mounts it and writes data. Later, they run 'xfs_info /mnt/data' and see the filesystem was created with default settings. What is the default inode size for XFS on a typical Linux system?

An administrator needs to view a list of users who have logged in recently. Which command provides this information?

Which TWO commands can be used to display real-time process resource usage on a Linux system? (Choose two.)

Refer to the exhibit. The output of 'ip addr show' reveals that eth0 is in state DOWN and has no IPv4 address. Which command is most likely to bring the interface up and obtain an IP via DHCP?

Which TWO commands can be used to check whether a systemd service is currently running?

A support engineer must copy the directory /srv/appdata, including every subdirectory, hidden file, and preserved permission bits and timestamps, to /backup/appdata on the same host. Which command accomplishes this?

A Linux server acting as a VPN gateway uses an nftables ruleset in the inet filter table. The administrator wants all forwarded traffic from the 10.8.0.0/24 VPN subnet to the 192.168.50.0/24 LAN to be accepted, while dropping any other forwarded traffic. Which nftables rule should be added to the forward chain to accomplish this?

Which TWO commands can be used to display the contents of a text file page by page? (Select two.)

Which THREE conditions must be met for a Linux system to function as a router between two networks?

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

A custom service requires that the network is fully operational before it starts. Which directive should be added to the [Unit] section of the service's unit file to ensure this dependency?

Which TWO commands can be used to check the status of the sshd service on a system using systemd?

An administrator is configuring a bridge using iproute2. Which command correctly attaches eth0 to bridge br0?

A Linux administrator is troubleshooting a custom systemd service named backup.service that fails to start. They run systemctl status backup.service and see that the service is in a failed state, but the output does not show detailed error messages. Which command should they use to view the most recent log entries specifically for this service?

A system administrator needs to configure a systemd service so that it restarts automatically only when it exits with a non-zero exit code, but not when it is cleanly stopped by an administrator. The service unit file currently has no Restart directive. Which combination of directives should the administrator use?

A user reports that a background process (PID 3456) is consuming 95% of CPU and causing system slowness. The process name is 'crypto-miner'. The administrator needs to immediately stop this process and ensure it does not restart. Which set of commands should the administrator execute?

A systems administrator needs to add a new user 'jdoe' with a home directory in /export/home, a UID of 1500, and an expiry date of 2025-12-31. Which command should they use?

A company has a server with two network interfaces: eth0 (192.168.1.10/24, gateway 192.168.1.1) and eth1 (10.0.0.10/24, gateway 10.0.0.1). The server needs to reach a remote network 172.16.0.0/16 via a VPN tunnel that terminates at 10.0.0.5 on eth1. Which command should be used to add a route for this traffic?

A Linux server has a single interface ens3 with address 203.0.113.10/24. The administrator runs `ss -tulnp` and sees that a service is listening on 127.0.0.1:8080 only. Remote clients on the Internet report they cannot reach the service on port 8080 even though the firewall allows the port. Which change is the most appropriate to allow remote access while preserving the service's intended exposure?

An administrator is troubleshooting a server that runs a critical application. The server has 16 GB of RAM and 8 CPU cores. The administrator notices that the server becomes very slow during peak hours. Analysis of 'iostat -x 1' shows that the average wait time (await) for the main disk (sda) is consistently above 1000 ms, while the average service time (svctm) is around 5 ms. What is the most likely cause?

An administrator wants to run a script daily at 2 AM. They create a timer unit and a service unit. The service unit uses Type=oneshot. Which of the following timer configurations is correct?

A storage administrator needs to identify which filesystem is mounted at /mnt/data and display the mount options currently in effect for it, using a single command that reads the kernel mount table. Which command should be used?

Arrange the steps to configure a new user account with sudo privileges on a Linux system.

A Linux administrator is configuring a new iSCSI storage target. The server has two network interfaces, eth0 and eth1, and the administrator wants to use multipath I/O (DM-Multipath) for redundancy and increased throughput. Which two steps are required to properly set up DM-Multipath for the iSCSI LUNs? (Choose two.)

An administrator is diagnosing a Linux router that forwards packets between two internal subnets. Users on 10.20.30.0/24 can reach hosts on 10.20.40.0/24, but responses from 10.20.40.0/24 arrive with the router's external address as the source. The administrator wants to inspect the NAT rules without modifying them. Which command displays the current rules in the nat table with packet and byte counters?

A Linux server has a volume group named vg_data that currently contains two physical volumes. The administrator needs to remove /dev/sdb1 from vg_data, but pvremove /dev/sdb1 returns an error stating the physical volume is still in use. Which command should the administrator run FIRST to migrate the extents off /dev/sdb1 onto the remaining physical volume?

A user is unable to write to a file. The output of 'ls -l file' shows '-r--r--r--'. Which command will grant write permission to the owner?

To view the system's default runlevel (target) at boot, which command is used on a systemd-based system?

A system administrator needs to set up software RAID1 on a server for /data. The available disks are /dev/sdb (500GB) and /dev/sdc (1TB). What is the maximum usable capacity of the RAID1 array?

Refer to the exhibit. A Linux administrator sees that 'myapp.service' is in a failed state with exit status 1. To troubleshoot, which command should the administrator use to view the full error output that the service produced before exiting?

An administrator wants to enforce that users in the 'contractors' group must change their password every 30 days, with a warning 7 days before expiry. Which command should be used?

Which TWO of the following commands can be used to check and repair an ext4 filesystem?

After a kernel update, a service fails to start with 'cannot allocate memory'. The system has 16GB RAM and 8GB swap. Which command should the administrator run first to diagnose potential memory limits?

Which THREE are common tools used for network troubleshooting on Linux?

A server uses LVM with volume group vg_data. The logical volume lv_app is mounted at /srv/app and is 200 GiB. The administrator adds a new 500 GiB disk, /dev/sdb, creates a physical volume on it, and extends vg_data with it. They then run lvextend -L +100G /dev/vg_data/lv_app. The filesystem is ext4. Which command must be run next to make the additional space usable without unmounting /srv/app?

A system administrator is troubleshooting network connectivity from a server that can reach internal resources but cannot access the internet. The server's /etc/sysconfig/network-scripts/ifcfg-eth0 file contains: BOOTPROTO=static, IPADDR=10.0.0.10, NETMASK=255.255.255.0, GATEWAY=10.0.0.1. The administrator runs 'ip route show' and sees: default via 10.0.0.1 dev eth0. However, 'ping 8.8.8.8' fails. Which is the most likely cause?

A developer reports that a compiled binary 'app' fails to execute with 'Permission denied' error when run from a mounted directory '/mnt/software'. The binary has execute permissions for all users. What is the most likely cause?

A user named 'charlie' has just been added to the 'devops' group. However, when 'charlie' runs 'sudo -l', no sudo entries are shown. What is the most likely cause?

A user wants to find the location of the 'grep' binary. Which command should they use?

Which TWO are valid methods to configure a network interface on a Linux system?

Which systemd unit type is used to group services and other units together for boot execution?

A user needs to view the contents of a compressed log file /var/log/syslog.gz without first decompressing it. Which command should they use?

A Linux administrator needs to display the IP addresses and netmasks of all network interfaces on a server. Which command provides this information in a concise, modern format?

A Linux server at a hosting provider uses a software RAID 5 array with three 2 TB disks (sda, sdb, sdc) configured as /dev/md0, hosting a large ext4 filesystem. The server experiences a performance degradation and I/O errors. The administrator checks /proc/mdstat and sees that /dev/sda is marked as failed. The remaining two disks are still active. The administrator has a spare disk /dev/sdd of the same size. The filesystem is sparse and can tolerate downtime. What is the most appropriate course of action to restore the array to a fully functional state with redundancy?

Which tool is the recommended method for persistently configuring network interfaces in RHEL 8?

A server is running out of disk space. Which command will show the disk usage of the root filesystem in a human-readable format?

Order the steps to configure a cron job that runs a script every day at 2 AM.

Which TWO commands can be used to display the routing table on a Linux system? (Choose two.)

A Linux server is experiencing performance issues. The administrator suspects that a process is causing excessive disk I/O. Which command should the administrator use to identify the process with the highest disk I/O usage in real-time?

To compress a file while preserving the original file, which command should be used?

An administrator needs to encrypt a block device (/dev/sdc) using LUKS. Which command creates an encrypted LUKS container on the device?

An administrator is creating a systemd timer unit called backup.timer that should trigger backup.service every day at 2:00 AM. The timer should also run the service immediately if the system was powered off at 2:00 AM. Which timer directives are required to achieve this?

Which command shows the default target for systemd?

Refer to the exhibit. The /var partition is 100% full. Which command can be used to find the largest files in /var/log to free up space?

An administrator runs 'systemctl status sshd' and sees the output above. The administrator wants sshd to start automatically at boot. Which command should be used?

An administrator has created an LVM thin pool. Which command should be used to create a thin logical volume named 'thinvol' of size 100GB from the thin pool 'pool1' in volume group 'vg1'?

A Linux server uses LVM. The volume group vg_data has 10 GB of free extents. The logical volume /dev/vg_data/lv_app is 20 GB and must be increased by 5 GB while it is mounted and actively used by an application. Which command sequence correctly extends the logical volume and then grows the ext4 filesystem online?

Which command enables a service to start automatically at boot in a systemd-based system?

You manage a Linux server that provides DHCP services to a small office network using the dhcpd daemon. The server has two network interfaces: eth0 (192.168.1.1/24) serving the internal network, and eth1 (192.168.0.1/24) connected to a DMZ. The DHCP server is configured to serve addresses only on eth0. Users on the internal network report that they are not receiving IP addresses. You check the DHCP server and find that the dhcpd service is running and listening on UDP port 67. From a client, you run tcpdump and see DHCPDISCOVER packets being sent, but no DHCPOFFER from the server. You also verify that no firewall rules are blocking DHCP traffic on either side. What is the most likely reason for the failure?

A system administrator is troubleshooting network connectivity from a Linux server to a remote host at 10.0.0.1. The server has a default gateway of 192.168.1.1. Running `ping 10.0.0.1` fails, but `ping 192.168.1.1` succeeds. The output of `ip route show` shows a default route via 192.168.1.1. Which additional step should the administrator take to further investigate?

A user reports that they cannot log in via SSH, but other users can. The administrator checks /var/log/auth.log and sees 'Failed password for invalid user'. What is the most likely cause?

A Linux server has an interface eth0 with IP 192.168.1.100/24. You need to temporarily add a secondary IP address 192.168.1.101/24 to the same interface for testing, and then verify that both addresses are present. Which two commands will accomplish this? (Choose two.)

A system administrator configures a new server with multiple disks. After partitioning and formatting, they mount a partition to /data. Several days later, they notice that the /data filesystem is full, but 'du -sh /data' reports only 2 GB used, while the partition is 100 GB. 'df -h' shows /data is 98% full. What is the most likely cause and the correct action?

A system administrator needs to schedule a one-time task that will run at 2:30 AM on July 15. Which command should be used to create this job?

An administrator needs to ensure that a custom service, /usr/local/bin/monitor.sh, starts automatically at boot and is restarted if it crashes. The service should run as user 'monitor' and should not depend on network being online. Which systemd unit file configuration is most appropriate?

A system administrator needs to list all files in the current directory, including hidden files, in a long listing format sorted by modification time (oldest first). Which command achieves this?

A system administrator wants to configure a custom service to start automatically at boot. Which command accomplishes this?

A server is experiencing high load, and the administrator suspects a runaway process is consuming excessive CPU. The administrator wants to identify the top CPU-consuming processes and then terminate the most resource-intensive one. Which sequence of commands should the administrator use?

A system running RHEL 8 experiences intermittent crashes. After reboot, 'journalctl -p err -b -1' outputs: 'PID 1234 (myapp) ended due to signal: KILL'. Which diagnostic step should the administrator perform next?

Which command can be used to display the UUID of a filesystem on /dev/sdb1?

A user needs to view the contents of a large text file one screen at a time. Which command is best for this?

A Linux server has a volume group named vg_data that contains a logical volume lv_archive currently formatted with XFS and mounted at /archive. The administrator needs to shrink the logical volume to free space for a new logical volume. Which command sequence correctly reduces the size of lv_archive?

A junior administrator needs to mount an ISO image located at /opt/install.iso to the /mnt/iso directory to access its contents. Which command accomplishes this?

A process (PID 1234) is hung and cannot be killed with SIGTERM. To force termination, which signal should be sent?

A Linux router has two interfaces: wan0 with address 198.51.100.10/24 and lan0 with address 10.10.0.1/24. Hosts on 10.10.0.0/24 can ping the router's lan0 address but cannot reach any Internet host. The administrator has already enabled net.ipv4.ip_forward=1. Which command is required to allow the internal hosts to reach external networks?

Which THREE of the following are valid directives for the [Service] section of a systemd unit file?

Which THREE commands can change the priority of an already running process?

What is the purpose of the chmod 755 command in this exhibit?

A Linux administrator needs to temporarily stop a service named 'httpd' without disabling it from starting automatically on subsequent boots. Which command should be used?

A server running Ubuntu 20.04 uses netplan for network configuration. The admin wants to set a static IP address 10.0.0.100/24 on interface enp0s3 with gateway 10.0.0.1 and DNS servers 8.8.8.8 and 8.8.4.4. Which YAML configuration is correct?

A system administrator wants to change the default runlevel (target) of a Linux system from graphical.target to multi-user.target. Which command should they use?

Which of the following commands can be used to display the total, used, and available space for all mounted ext4 filesystems?

Which THREE of the following are valid Linux filesystem types that can be used for root partitions on a modern Linux system?

Which TWO commands can be used to mount a filesystem on /dev/sdb1 to /mnt/data?

A system administrator needs to change the group ownership of a file to 'developers' and set the setgid bit on a directory. Which two commands accomplish these tasks? (Choose two.)

A user reports that they can access websites by IP address but not by domain name. Which command should the administrator use to diagnose the issue?

A Linux administrator is creating a custom systemd timer unit named backup.timer to schedule a daily backup script. The administrator wants the timer to trigger the backup service exactly at 2:00 AM every day, regardless of when the system was last booted. Which timer directive should be used in the [Timer] section of backup.timer?

A Linux server needs to resolve the hostname db.internal.example.com to an IP address. The administrator wants to query the DNS server directly without relying on the local resolver cache. Which command should be used?

A junior administrator has installed a new 4 TB SATA disk as /dev/sdb on a RHEL 9 server and wants to use it as a single XFS filesystem mounted at /data. The disk currently has no partition table. Which command should be run first to create an XFS filesystem directly on the whole device?

A system administrator is creating a systemd service unit for a custom application. The application requires that a specific environment variable, APP_ENV=production, be set before the service starts. The administrator wants this variable to be available only to this service, not system-wide. Which directive should be used in the service unit file?

A developer needs to temporarily allow incoming TCP connections on port 8080 for testing. Which iptables command adds a rule to the INPUT chain to accept this traffic?

A Linux server's root filesystem is filling up quickly. You suspect that a user's process is writing a large log file and that the file has been deleted, but the space is still held. Which command will show the deleted file and the process holding it open?

A system administrator needs to create a new ext4 filesystem on /dev/sdb1 with a reserved block percentage of 2% instead of the default 5%. Which command should be used?

Which TWO commands can be used to display the current working directory? (Choose exactly two.)

A security audit reveals that a sensitive file '/etc/shadow' has been modified. The file's permissions are set to 600 and owned by root. However, the audit logs show that a service account 'webapp' was able to read the file. The 'webapp' user is not in the root group. Which of the following is the most likely method the 'webapp' user used to read the file?

A Linux administrator is configuring a custom systemd service called backup.service. The service should run a backup script only when the server is connected to AC power and not running on battery. Which condition directive should be added to the [Unit] section of backup.service?

Which command displays the current status of all active services?

An administrator wants to view the current memory usage in a human-readable format, showing totals for used and free memory. Which command should be used?

A security analyst needs to search for the literal string 'error: failed to connect' in all .log files under /var/log, including subdirectories. The search should be case-insensitive and display line numbers. Which command should they use?

An administrator needs to allow incoming SSH connections on port 22 from the 192.168.50.0/24 subnet while blocking all other incoming SSH traffic, without disrupting existing established connections. Which command sequence using nftables accomplishes this?

A Linux server has its time zone set to UTC, but the administrator wants the system clock to be synchronized by an internal NTP server at 10.0.0.10. The system uses systemd and chrony is already installed. Which command should the administrator run to configure the NTP server and make it persistent?

A junior administrator needs to create a symbolic link named /usr/local/bin/editor that points to /opt/tools/vim.bin. The link must be created without overwriting any existing file at the destination. Which command accomplishes this?

Based on the tcpdump output in the exhibit, what can be concluded about the TCP handshake?

A developer wants to change the ownership of a directory and all its contents recursively to user 'appuser' and group 'appgroup'. Which command accomplishes this?

A user wants to view the contents of a compressed file file.txt.gz without decompressing it permanently. Which two commands can be used? (Choose two.)

An administrator is auditing a server and needs to list only the users whose primary group is 'developers'. The system has many users, and the administrator wants a precise, scriptable one-liner that parses /etc/passwd. Which command accomplishes this?

A user needs to see the contents of a gzip-compressed file 'data.txt.gz' without decompressing it. Which command is appropriate?

A Linux administrator needs to ensure that the 'httpd' service starts automatically at boot and is currently running. The system uses systemd. Which two commands should the administrator use to achieve this? (Choose two.)

An administrator needs to set the reserved block percentage on an ext4 filesystem to 1% for a non-root filesystem. Which command accomplishes this?

A system administrator needs to identify which processes are consuming the most CPU and memory on a Linux server. Which TWO commands can provide a real-time, interactive view of process resource usage? (Choose two.)

An administrator needs to mount an XFS filesystem with options to optimize for a database workload. Which mount option would reduce metadata updates to improve performance?

An administrator needs to replace all occurrences of the string 'foo' with 'bar' in all files under /etc/config, but only in files ending with .conf. The replacement must be done in-place, and backup copies should be created with a .bak extension. Which command accomplishes this?

A server runs a custom application that listens on TCP port 8080. The administrator wants to ensure the application starts automatically on boot and restarts if it crashes. Which systemd unit file directive should be used to achieve the restart behavior?

A system administrator needs to configure a static IP address on a CentOS 7 server. Which file should be edited to set the IP address permanently?

To check the disk usage of the /var/log directory in a human-readable format, which command is appropriate?

An administrator runs 'ls -la' and sees the following entry for a file: 'lrwxrwxrwx 1 root root 24 Jan 10 12:00 link -> /etc/passwd'. If the target file /etc/passwd is deleted, what happens to the link file?

A user reports that they cannot reach a remote server by hostname but can reach it by IP address. Which configuration file is most likely misconfigured?

A system administrator needs to check the current CPU load and memory usage on a Linux server. Which command should be used to display a dynamic, real-time view of running processes and system resource utilization?

A Linux server running NetworkManager has a Wi-Fi interface wlp3s0 that must connect to the corporate WPA2-Enterprise network 'CorpNet' with 802.1X PEAP authentication, using identity 'jdoe' and password 'S3cr3t!'. The administrator wants to create and activate this connection entirely from the command line without editing configuration files manually. Which sequence of commands will accomplish this?

An administrator wants to print the last field of each line from a CSV file 'data.csv' (comma-separated). Which awk command accomplishes this?

A network interface eth0 is not receiving an IP address via DHCP. Which command can be used to troubleshoot the DHCP client process?

A junior administrator has written a custom systemd service unit file named backup.service in /etc/systemd/system/. The unit is intended to run a backup script once per day. After placing the file, the administrator runs systemctl start backup.service, but systemd reports 'Unit backup.service not found.' The file exists and has correct syntax. Which command should the administrator run to make systemd aware of the new unit file?

A temporary contractor 'contractor1' has left the company. The administrator needs to remove the user account and all associated files in the home directory. Which command accomplishes this?

A Linux server has a single XFS filesystem mounted at /data on /dev/sdb1. The storage array behind /dev/sdb1 is expanded and the block device is now 2 TB instead of 1 TB. The administrator confirms that the kernel sees the larger device with blockdev --getsize64 /dev/sdb1. Which command should be run to make the additional space usable by the mounted /data filesystem?

A Linux server has a single network interface enp3s0 that must obtain its IPv4 address automatically from a DHCP server on the local subnet. The administrator prefers to manage this connection with NetworkManager and wants the setting to persist across reboots. Which command will configure the connection profile named 'Wired connection 1' to use DHCP?

A technician must locate every regular file beneath /var that is larger than 100 MB and was modified more than 30 days ago, then list them. Which TWO find expressions achieve this? (Choose two.)

A system administrator notices that a process is consuming 100% CPU and is unresponsive. Which command should be used to immediately stop the process if the PID is 2345?

An admin notices a PV in a VG has failed. The VG is still accessible with redundancy. Which command sequence should be used to replace the faulty PV with a new one (/dev/sde) while the VG is active and without data loss?

After extending the logical volume, the df output still shows 100G. What is the most likely reason?

A Linux administrator is configuring a custom systemd service that must not start until a network share is mounted. The mount is managed by a systemd mount unit named mnt-data.mount. Which directive should be added to the [Unit] section of the service unit to enforce this ordering?

A systems administrator is troubleshooting a server that runs a database application. The server has 64 GB of RAM and 16 CPU cores. The administrator notices that the system is using a significant amount of swap space even though there is plenty of free memory. The 'free -m' command shows: total memory = 65536, used = 50000, free = 15536, buffers/cache = 10000, swap total = 8192, swap used = 6000. Which of the following is the most likely cause?

A Linux server is experiencing performance degradation. The administrator suspects that a process is consuming excessive CPU. Which two commands can be used to identify the top CPU-consuming processes in real-time? (Choose two.)

Which TWO commands can be used to display the group membership of a user? (Choose two.)

An administrator needs to assign a temporary IPv4 address of 10.20.30.40/24 to interface enp0s3 for immediate testing. The change should not persist after a reboot. Which command accomplishes this?

Which THREE actions will affect the state of a systemd service that is currently running? (Choose three.)

An administrator has enabled quotas on the /home filesystem by adding usrquota,grpquota to /etc/fstab and remounting. Then ran quotacheck -cug /home and it completed successfully. However, users are still able to write beyond their assigned soft limits. What step is missing?

You are managing a Linux server that hosts a shared project directory /projects/alpha, owned by the group 'alpha' (GID 2001). The directory has permissions 2770 (setgid, rwx for owner and group, no access for others). User 'jane' (UID 1501) has a primary group 'staff' (GID 1001) and is not in the 'alpha' group. She reports being unable to list or modify files in /projects/alpha. You need to give her access as a member of the 'alpha' group without changing her primary group. Which command sequence should you use?

Which TWO commands can be used to view the last 10 lines of a file and also follow new lines as they are written?

Based on the exhibit, which process is using the most physical memory (RES)?

You administer a Linux server that acts as a network gateway. It has two network interfaces: eth0 (external, with IP 203.0.113.10/24, gateway 203.0.113.1) and eth1 (internal, with IP 192.168.1.1/24). The server is running firewalld and has IP forwarding enabled. Internal hosts (192.168.1.0/24) can access the internet through NAT, which is configured using firewalld's masquerade on the external zone. However, you need to allow a specific internal server (192.168.1.100) to be reachable from the internet on TCP port 443 (HTTPS). You add a port forwarding rule using firewall-cmd: 'firewall-cmd --zone=external --add-forward-port=port=443:proto=tcp:toport=443:toaddr=192.168.1.100'. After reloading the firewall, external users still cannot connect to 203.0.113.10:443. You verify that the internal server is running HTTPS and that its local firewall allows port 443. What is the most likely reason the port forwarding is not working?

A junior administrator needs to verify that the host can resolve the name db.internal.example.com to an IPv4 address before deploying a database client. The system uses systemd-resolved. Which command queries the configured resolver and displays the answer without relying on the local nsswitch.conf ordering?

A Linux server hosts a shared project workspace at /srv/design. The directory is owned by root and currently has permissions 0775 with group ownership set to the 'designers' group. A new file was just created inside /srv/design by user 'mira' (a member of designers), and the file's group is showing as 'mira' instead of 'designers'. The team lead wants every NEW file and subdirectory created under /srv/design to automatically inherit the 'designers' group, while leaving existing files untouched. Which command should the administrator run?

A server must resolve internal hostnames using a DNS server at 10.0.0.53 before falling back to public resolvers. The administrator edits /etc/systemd/resolved.conf and sets DNS=10.0.0.53 and FallbackDNS=8.8.8.8. After restarting systemd-resolved, queries for internal names still fail. Which additional step is most likely required?

An administrator needs to view the current IPv4 addresses, link state, and interface names on a Linux server without making any changes. Which command provides this information in a single invocation?

A server needs to forward packets between two networks: 10.0.1.0/24 on eth0 and 10.0.2.0/24 on eth1. Which sysctl parameter must be enabled?

A Linux administrator is configuring a systemd service that must only start after the network is fully online and must stop if the network goes down. The unit file currently has After=network.target. However, the service sometimes starts before DNS resolution is available, causing failures. Which target should the administrator use instead to ensure the network is fully configured and DNS is available?

An administrator needs to add a 2 GB swap area that persists across reboots on a server with no free partition space, using a file at /swapfile on the root filesystem. After creating the file with fallocate and running mkswap /swapfile, which additional actions are required to activate it now and at every boot?

Which THREE of the following commands can be used to search for a string in multiple files and display the matching lines?

A junior administrator needs to create a compressed archive of the /etc directory that preserves file ownership and permissions, and writes it to /backup/etc.tar.gz. Which single command accomplishes this?

An administrator wants to limit the CPU usage of a service to at most 50% of a single CPU core. Which directive should be set in the [Service] section of the unit file?

A Linux server is configured with two network interfaces: eth0 (192.168.1.10/24) and eth1 (10.0.0.10/24). The default route is via 192.168.1.1. A network administrator wants to ensure that traffic to the 10.0.0.0/24 network uses eth1 and that the source address for that traffic is 10.0.0.10. Which command will achieve this?

Order the steps to configure a static IP address on a CentOS/RHEL 7 system using ifcfg files.

A Linux administrator needs to schedule a backup script to run every day at 2:30 AM. The script is located at /usr/local/bin/backup.sh. Which command should the administrator use to edit the crontab for the root user?

An administrator is preparing a new server with two unused disks, /dev/sdb and /dev/sdc, for a software RAID 1 array that will hold customer data. Which two commands are required to create the array and make it usable? (Choose two.)

Which two statements are true about LVM snapshots? (Choose two.)

A technician needs to view the current IPv4 addresses, netmasks, and interface states for all network interfaces on a Linux server. Which command displays this information in a structured, modern format?

A system administrator needs to check the firewall rules on a Linux server using firewalld. Which two commands can be used to list the current rules? (Choose two.)

Scenario: You are managing a Linux server that hosts a web application. The application runs under the user 'webapp' and the group 'webgroup'. Recently, a new intern 'john' (username 'john') needs to be able to view and modify files in /var/www/html, which is owned by root:webgroup with permissions 775. John is currently a member of the group 'staff', but not 'webgroup'. The security policy requires that John must be able to edit files without using sudo, and his primary group must remain 'staff'. Which of the following actions should you take to meet the requirements?

Which THREE files or directories are commonly used to configure network interfaces on a RHEL/CentOS system?

A junior administrator needs to check the current system time and date on a Linux server. Which command will display this information?

A storage administrator is troubleshooting a system where a new SCSI disk is detected by the kernel but not visible in /dev/disk/by-id/. What is the most likely cause?

An administrator is configuring LVM and wants to display information about physical volumes, volume groups, and logical volumes. Which two commands provide this information? (Choose two.)

A junior administrator needs to add a new 2 TiB disk, /dev/sdc, to a server and create a single GPT partition that spans the entire disk. The disk currently has no partition table. Which command will create the GPT partition table and the partition in one interactive session?

A user reports that they cannot run a script because it says 'Permission denied'. The script is owned by root and has permissions -rw-r--r--. Which command would allow the user to execute the script?

A Linux server's root filesystem is running out of space. The administrator needs to identify which directory under /var is consuming the most disk space. Which command should the administrator use?

A DevOps engineer is writing a continuous integration pipeline that runs a script to deploy an application. The script is stored in a Git repository and is executed on a build server. The script works locally on the engineer's workstation, but when executed on the build server, it fails with '/bin/sh: line 12: somecommand: command not found'. The 'somecommand' is a standard Linux tool that is installed on the build server. The build server uses a minimal Docker container. Which of the following is the most likely cause and solution?

A large e-commerce platform runs on a database server that uses LVM thin provisioning. The thin pool is overcommitted at 200% (pool size 1TB, thin volumes total 2TB). Suddenly, the database reports write errors and performance degrades drastically. The administrator checks the system and finds that the thin pool is completely full. What is the immediate effect on the thin volumes, and what should the administrator do to restore normal operation without data loss?

A system administrator needs to create a shared group 'projectx' and add existing users 'bob' and 'carol' to it. The users need to collaborate on files in a directory /projectx. What is the correct sequence of commands to set up the group and ensure new files created in /projectx are automatically owned by the group 'projectx'?

After deleting user 'alice', the system administrator wants to also remove the home directory and mail spool. Which command should be used?

Match each Linux boot component to its description.

Given the network interface configuration in the exhibit, which command should be run to apply the configuration without rebooting?

A junior administrator needs to mount the XFS filesystem on /dev/sdb1 at /srv/files for the current session only, without creating a persistent entry. Which command accomplishes this?

A Linux server uses NetworkManager and has a wired connection profile named 'Wired connection 1'. The administrator needs to set a static IPv4 address 10.20.30.40/24 with gateway 10.20.30.1, and ensure the change persists across reboots. Which sequence of commands accomplishes this?

A system administrator needs to ensure that the /dev/sdb1 filesystem is automatically mounted at /data with the noatime option at boot. The filesystem's UUID is known. Which entry in /etc/fstab is correct?

A server's root filesystem is filling up. An administrator needs to find the largest regular files under /var, sorted from largest to smallest, while avoiding errors from unreadable directories that are not owned by the administrator. Which command is most appropriate?

An administrator wants to see the disk usage of the /var directory in a human-readable format. Which command should be used?

An administrator is troubleshooting DNS resolution and wants to query the SOA record for a domain. Which three commands can be used? (Choose three.)

A server has two NICs bonded in mode 1 (active-backup). If the active NIC fails, what occurs?

An administrator needs to configure a service to run as a non-root user for security reasons. Which systemd unit file directive accomplishes this?

A junior administrator has a USB flash drive at /dev/sdb that will be used exclusively as a data disk on a Linux server. They need to create an XFS filesystem on the whole device (no partitions). Which command accomplishes this?

A Linux server has a single network interface ens3. You need to assign the static address 10.10.10.5/24 with gateway 10.10.10.1 using NetworkManager. The connection profile is named 'static-ens3'. Which command correctly applies the IPv4 address, disables DHCP, and sets the gateway, all in one step?

A junior administrator must temporarily assign the address 172.16.5.20/24 to interface eth1 on a running server so that a migration can be tested, and the change must not survive a reboot. Which command accomplishes this?

Existing user 'jdoe' is a member of groups 'users' (primary) and 'staff'. The administrator needs to add 'jdoe' to group 'projectx' while preserving existing supplementary group memberships. Which command achieves this?

A Linux server is configured as a router with IP forwarding enabled. It has two interfaces: eth0 (203.0.113.5/24) and eth1 (192.168.1.1/24). Clients on 192.168.1.0/24 need to reach the internet via eth0. The administrator has set up NAT using iptables with the rule: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE. However, clients cannot access external websites. Which two actions should the administrator take to resolve the issue? (Choose two.)

An administrator is troubleshooting a server with a software RAID 1 array on /dev/md0. One disk, /dev/sdc, has failed and been replaced. The administrator runs `mdadm /dev/md0 --add /dev/sdc1` and sees the array rebuilding, but after a reboot the new disk is no longer part of the array. Which action should the administrator take to ensure the replacement disk is automatically reassembled into the array at boot?

An administrator is troubleshooting a server where the root filesystem is on an LVM logical volume. The system fails to boot and drops to an initramfs prompt with the error 'Volume group "vg_root" not found'. The administrator verifies that the physical volumes are present and the volume group exists when booting from a rescue disk. Which action is most likely to resolve the boot issue?

An administrator manages a server with several iSCSI LUNs attached. The server reboots after a kernel update, and one of the LUNs, which previously appeared as /dev/sdc, is now enumerated as /dev/sdd, breaking an /etc/fstab entry that references /dev/sdc. The administrator wants to make the mount configuration resilient to device-name changes and to avoid boot delays if the LUN is temporarily missing. Which two actions should the administrator take? (Choose two.)

Which THREE commands can be used to view the contents of a file?

Which THREE files are directly related to user and group management in a Linux system? (Select three.)

A system administrator needs to find all files in /var/log that have been modified in the last 7 days. Which command accomplishes this?

Match each systemd unit type to its purpose.

A system administrator notices that '/var/log/syslog' has grown very large and is consuming significant disk space. The administrator wants to identify the largest log files in the '/var/log' directory hierarchy. Which command should the administrator use?

A system administrator is troubleshooting a production web server running CentOS 7 that became unresponsive. The server is still pingable, but SSH connections timeout. The admin performs an out-of-band console login. The server appears frozen; typing commands shows no output. The admin is able to trigger a Magic SysRq key sequence (Alt+SysRq+f) to kill the hung processes. After that, the server resumes normal operation. However, the admin wants to understand the root cause. Upon checking 'dmesg', they see repeated messages: 'NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!' followed by stack traces from a kernel thread. Which action should the admin take to prevent recurrence while maintaining system stability?

A junior administrator needs to identify the filesystem type of the device /dev/nvme0n1p2 on a running Linux server without mounting it or modifying any metadata. Which command should be used?

Which TWO commands can be used to resolve a hostname to an IP address?

A support engineer must copy the file /etc/hosts to /tmp/hosts.backup but only if /tmp/hosts.backup does not already exist, so that an existing backup is never overwritten. Which command performs this conditionally?

A Linux administrator is configuring a systemd service unit for a custom application. The application requires that the /opt/app/data directory exists and is writable before the service starts. The administrator wants to ensure this directory is created automatically if it does not exist. Which systemd directive should be added to the [Service] section to achieve this?

A junior administrator needs to add user 'mchen' to the supplementary group 'developers' without removing existing group memberships. Which command should be used?

To check the details of a failed systemd service unit, including the last log entries, which command is most appropriate?

An administrator needs to add a new swap space to a running Linux server without rebooting. The server has a free partition /dev/sdc1 and an existing file /swapfile. Which two commands or steps are required to activate the new swap partition /dev/sdc1 immediately? (Choose two.)

Which TWO commands can be used to display listening TCP ports on a Linux system?

A system administrator needs to prevent a service named backup.service from starting automatically at boot, while keeping it available for manual start. The service is currently enabled. Which command should the administrator run?

A Linux server has a DNS resolver configuration in /etc/resolv.conf. You need to add a new DNS server at 8.8.8.8 and ensure it is used before the existing server. Which line should you add to the top of /etc/resolv.conf?

An administrator needs to add a new 8 GB swap area on a server that already has a 2 GB swap partition. The system has free space in the volume group vg_sys. Which command creates a logical volume named lv_swap of exactly 8 GB and prepares it for swap use?

An administrator needs to inspect the first few lines of a very large log file /var/log/syslog without loading the entire file into memory, and also needs to follow new entries as they are appended in real time. Which TWO commands or command combinations satisfy these requirements? (Choose two.)

Refer to the exhibit. The administrator attempted to create a user 'newuser' but received an error. Which command should be used to check if the user already exists?

A storage administrator is preparing a 4 TB USB 3.0 external drive to hold large backup archives. The drive must be usable on Linux, Windows, and macOS workstations, and single files will occasionally exceed 4 GB. Which filesystem should be created on the single partition /dev/sdb1?

A server has a new disk /dev/sdd that must be mounted at /backup and automatically mounted at boot. The administrator creates a GPT partition table, a single partition /dev/sdd1, and an ext4 filesystem. Which /etc/fstab entry correctly uses a persistent identifier for the filesystem?

An administrator needs to compress a directory named 'project' into a tarball with maximum compression using gzip. Which command is appropriate?

An administrator wants to ensure that a service is listening on TCP port 8080 and accessible from remote hosts. Which command will confirm that the service is listening on the correct interface?

A junior administrator needs to display the first 10 lines of a file named 'data.csv'. Which command should they use?

An administrator is investigating why the 'tomcat' service fails to start on a RHEL 8 server. The output of 'systemctl status tomcat' shows: 'Loaded: loaded (/etc/systemd/system/tomcat.service; enabled; vendor preset: disabled) Active: failed (Result: exit-code) since ... Process: 4567 ExecStart=/opt/tomcat/bin/startup.sh (code=exited, status=1/FAILURE)'. The 'journalctl -u tomcat' shows: 'Error: JAVA_HOME is not defined correctly, cannot execute /usr/lib/jvm/java-11-openjdk/bin/java'. The admin checks /opt/tomcat/bin/startup.sh and sees it references JAVA_HOME. The admin verifies that Java 11 is installed at /usr/lib/jvm/java-11-openjdk. Which action should the admin take to fix the service?

A user reports that a script fails with 'Permission denied' when executed. The script has permissions -rw-r--r-- and is owned by the user. Which command should the user run to make the script executable for the owner only?

Which THREE of the following statements about the user private group (UPG) scheme are true?

A Linux router has two interfaces: eth0 (203.0.113.10/24) connected to the internet and eth1 (10.10.0.1/24) connected to an internal network. Internal clients can ping the router's eth1 address but cannot reach external websites. IP forwarding is enabled, and no firewall rules are present. Which command will allow the internal clients to reach the internet by masquerading their traffic?

An administrator is configuring an NFS server and wants to export /srv/data to a specific client, 192.168.10.25, with read-write access, while ensuring that the client's root user is mapped to the anonymous user for security. Which entry should be placed in /etc/exports?

Which THREE steps are required to create a new ext4 filesystem on /dev/sdc1 and ensure it is automatically mounted at /mnt/data at boot? (Choose three.)