System Architecture

Which command shows the amount of free and used memory in the system, including swap?

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 Linux workstation appears to hang early in the boot process after the initramfs is loaded. The administrator wants to add kernel boot parameters temporarily from the GRUB 2 menu without making a permanent change. Which action should the administrator take?

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

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

A Linux server uses a systemd-based init and has several custom services. The administrator wants to inspect the runtime state and configuration of a unit named backup.service without starting or stopping it. Which TWO commands provide information about this unit? (Choose two.)

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?

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 technician must determine whether a Linux server's CPU supports hardware-assisted virtualization so the host can run KVM guests. The technician needs to inspect the processor flags exposed by the running kernel. 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 Linux server has two hot-swappable SATA drives that are part of a software RAID 1 array. The administrator needs to replace one drive while the system is running, but first wants to verify the current status of the array to ensure it is not degraded. Which command will display the detailed status of the mdadm array?

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 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 Linux server uses a custom udev rule to assign a persistent name to a USB-to-serial adapter. After a kernel update, the adapter is no longer recognized by its custom name, and the administrator finds that the rule file is still present. Which command should be used to reload the udev rules and trigger them for existing devices without rebooting?

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 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 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 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.

A minimal Linux system boots using a legacy BIOS with GRUB 2 installed in the MBR of /dev/sda. The administrator wants to install a new boot loader configuration that writes the boot code to the MBR and also places core.img in the gap between the MBR and the first partition. Which command accomplishes this?

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?

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

A Linux workstation fails to boot and drops to a GRUB prompt. The administrator needs to inspect the available disks and partitions from within the GRUB environment before attempting recovery. Which command lists block devices and partitions recognized by GRUB?

A technician needs to identify the hardware installed on a Linux workstation. The technician runs a command that prints a hierarchical tree of PCI devices showing vendor and device IDs, along with the kernel driver in use. Which command was most likely executed?

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?

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

A system administrator is troubleshooting a server that takes a long time to boot. The administrator wants to identify which systemd units are slowing down the boot process. Which TWO of the following commands can be used to analyze boot performance? (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?

A technician is diagnosing a server that fails to reach the expected multi-user target. The technician wants to gather evidence about kernel ring buffer messages and the systemd journal for the current boot. Which TWO commands provide this diagnostic information? (Choose two.)

A Linux administrator is troubleshooting a server that intermittently fails to detect a newly installed network card. The administrator suspects the kernel is not loading the correct driver automatically. Which TWO commands should be used to identify the PCI device and then load the appropriate kernel module manually? (Choose two.)

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?

An administrator needs to inspect the hardware inventory of a server, including details about the motherboard, BIOS, and memory banks, in a structured way. Which command provides this information by reading from the DMI/SMBIOS data?

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

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

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

Which TWO commands can display the UUID of block devices?

Which command displays information about currently loaded kernel modules?

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

A technician needs to output only the kernel release number. 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?

A Linux server has a USB serial adapter that is sometimes detected as /dev/ttyUSB0 and sometimes as /dev/ttyUSB1 after reboot. An administrator wants to create a udev rule that always assigns the name /dev/ttyUSB-radio to this specific adapter based on its serial number. Which udev rule syntax should be used?

A Linux administrator needs to determine which kernel modules are currently loaded on a running system. The administrator also wants to see the module dependencies and the use count for each module. Which command should be used?

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?

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

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

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?

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

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

Which TWO statements about GRUB 2 are correct?

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?

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

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

Match each ACL term to its meaning.

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

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

A system administrator needs to ensure that a custom kernel module named 'mydriver.ko' is loaded automatically at boot on a system that uses systemd. The module is located in /lib/modules/$(uname -r)/extra/. Which approach is most appropriate?

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?

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

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

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 are valid methods to reduce boot time on a Linux system? (Select exactly 2.)

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 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 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?

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.

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?

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?