LPIC-1 System Architecture Practice Test 6 — 15 Questions

Question 1

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

Accepted Answer

The bootloader installed in the ESP. In UEFI boot, the bootloader must reside in the EFI System Partition (ESP) as a file (e.g., /EFI/BOOT/BOOTX64.EFI) that the UEFI firmware can directly load. Option B is correct because the ESP must be formatted with FAT32 (or FAT16 for older systems) as per the UEFI specification, which requires a specific partition type (GUID C12A7328-F81F-11D2-BA4B-00A0C93EC93F for GPT) to store bootloaders and drivers.

Answer

The bootloader installed in the Master Boot Record (MBR)

Answer

A BIOS boot partition

Answer

A kernel with EFI stub support

Question 2

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?

Accepted Answer

mkswap /dev/sdb2. The `mkswap` command is specifically designed to initialize a partition or file as a swap area by writing a swap signature (UUID and swap superblock) to the device. After creating the partition, you must run `mkswap /dev/sdb2` to set it up for use as swap before activating it with `swapon`.

Answer

mkfs.ext4 /dev/sdb2

Answer

fsck /dev/sdb2

Answer

swapon /dev/sdb2

Question 3

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

Accepted Answer

systemctl enable sshd.service. The `systemctl enable sshd.service` command creates the necessary symlinks in the systemd unit configuration directories (e.g., `/etc/systemd/system/multi-user.target.wants/`) so that the sshd service is automatically started when the system boots into its default target. This is the correct way to enable a service to start at boot in a systemd-based Linux distribution.

Answer

systemctl start sshd.service

Answer

systemctl daemon-reload

Answer

systemctl set-default multi-user.target

Question 4

A system administrator is responsible for a Linux server running a critical application. The server recently experienced an unplanned power outage. Upon rebooting, the system fails to reach the default target and drops into an emergency shell. The administrator notices that the root filesystem (/) is mounted read-only. The /etc/fstab file contains the following lines:

UUID=abc123 / ext4 errors=remount-ro 0 1
UUID=def456 /home ext4 defaults 0 2
UUID=ghi789 none swap sw 0 0

The administrator suspects that the /home filesystem has a corrupt superblock and is causing the boot failure. The administrator needs to check and repair the /home filesystem without causing data loss. Which of the following is the correct course of action?

Accepted Answer

Boot from a live USB, run 'fsck /dev/sdb1' on the unmounted filesystem, then reboot.. The /home filesystem is suspected to have a corrupt superblock, and running fsck on an unmounted filesystem from a live USB is the safest way to check and repair it without risking further damage. The emergency shell mounts the root filesystem read-only, and /home cannot be reliably checked while mounted or without proper access to its device node. Booting from a live USB ensures the filesystem is not in use, allowing fsck to safely repair the superblock or use an alternate superblock if needed.

Answer

Reinstall the system from backup because the superblock corruption is fatal.

Answer

Run 'fsck /dev/sdb1' from the emergency shell after remounting /home read-write.

Answer

Run 'fsck -y /dev/sdb1' from the emergency shell, but first run 'mount -o remount,rw /home' to make the filesystem writable.

Question 5

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?

Accepted Answer

ipmitool sensor list. The `ipmitool sensor list` command queries the Baseboard Management Controller (BMC) via the IPMI protocol to retrieve real-time sensor readings (e.g., voltages, temperatures, fan speeds) and system event logs (SEL). This is the correct tool for diagnosing hardware-level issues like a failing power supply, as it provides direct access to the server's hardware health monitoring subsystem, independent of the operating system.

Answer

sensors -u

Answer

lspci -v

Answer

dmidecode -t baseboard

Question 6

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?

Accepted Answer

Boot from a live CD, chroot, and run 'update-initramfs -u -k all' to regenerate the initramfs with lvm2 support. The error 'Failed to mount the real root device' after a system upgrade indicates the initramfs lacks the necessary LVM modules (e.g., lvm2) to activate and mount the root logical volume. Regenerating the initramfs with 'update-initramfs -u -k all' rebuilds it to include LVM support, ensuring the kernel can locate and mount the root filesystem during boot.

Answer

Run 'lvchange -ay' to activate all LVs

Answer

Reinstall GRUB to the MBR

Answer

Use 'fsck' on the root LV

Question 7

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

Accepted Answer

lscpu. B is correct because `lscpu` is a dedicated command that reads and aggregates CPU architecture information from `/sys` and `/proc/cpuinfo`, presenting it in a clean, human-readable format. It provides details such as CPU model, cores, threads, architecture type, and cache sizes, making it a standard tool for CPU architecture queries on Linux.

Answer

uname -m

Answer

dmidecode -t processor

Answer

lspci

Question 8

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

Accepted Answer

oneshot. (oneshot) is correct because it is a valid systemd service unit type that defines a service where the main process runs once and exits, after which systemd considers the service as active. This is commonly used for tasks like filesystem checks or one-time initialization scripts.

Answer

runtime

Answer

exec

Question 9

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.

Accepted Answer

Run 'modprobe bonding' before ifup. The 'bond' kernel module must be loaded before the bonding interface can be created. Running 'modprobe bonding' loads the module into the kernel, making the bonding functionality available. Without this step, 'ifup bond0' fails because the kernel does not recognize the bonding driver.

Answer

Use ifenslave directly after ifup

Answer

Reboot the system to load the module

Answer

Add 'auto bond0' in /etc/network/interfaces

Question 10

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.

Accepted Answer

Run 'timedatectl set-ntp true' to enable systemd-timesyncd. On Ubuntu 20.04, systemd-timesyncd is the default NTP client. Running 'timedatectl set-ntp true' (option A) activates it, which automatically synchronizes the system clock with NTP servers, correcting the gradual drift without needing additional packages or manual cron jobs. This is the simplest and most appropriate single action for automatic time sync on a modern systemd-based distribution.

Answer

Add 'hwclock --hctosys' to /etc/rc.local

Answer

Install and configure the ntp package with a pool server

Answer

Use 'cron' to run ntpdate every minute

Question 11

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.

Accepted Answer

primary=eth0. The bond is in active-backup mode (mode 1) and eth0 is marked as 'up' but not 'active' after reconnection. Without the 'primary=eth0' parameter, the bond does not automatically switch back to the preferred slave (eth0) once it becomes available; it only fails over to eth1 when eth0 goes down. Setting 'primary=eth0' ensures that eth0 is always preferred as the active slave when it is in 'up' state, triggering a failback.

Answer

updelay=0

Answer

downdelay=0

Answer

miimon=100

Question 12

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

Accepted Answer

The service does not write its PID file quickly enough. The error message 'PID file /var/run/myservice.pid not readable (yet?) after start' indicates that systemd started the service and is waiting for the PID file to appear, but the file was not created within the default timeout (5 seconds for Type=forking). Since the service forks once, systemd expects the parent to exit and the child to write its PID to the file. If the daemon takes longer than TimeoutStartSec to write the PID file, systemd marks the unit as failed even though the process is still running. Option B, "The service does not write its PID file quickly enough," correctly identifies this timing issue. Option A, "The PIDFile path is wrong," is incorrect because the log message explicitly says the PID file is not readable *yet*, implying the path is correct but the file has not been written. Option C, "The service needs a TimeoutStartSec increase," is incorrect because TimeoutStartSec is not about the PID file creation; it's about the time systemd waits for the start operation to complete. Option D, "The unit file should use Type=simple instead," is incorrect because Type=simple would not wait for a PID file at all, but the service is designed to fork (which Type=simple cannot handle properly), and the error indicates systemd is expecting a PID file.

Answer

The PIDFile path is wrong

Answer

The service needs a TimeoutStartSec increase

Answer

The unit file should use Type=simple instead

Question 13

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

Accepted Answer

Run 'mdadm --run /dev/md0' to force start the array in degraded mode, then add sdc with 'mdadm --add' after system is up. Since the RAID5 array has only two of three disks available, it can still operate in degraded mode. The command 'mdadm --run /dev/md0' forces the array to start despite the missing device, allowing the system to boot from the root filesystem on md0. Once the system is operational, the admin can add the missing disk with 'mdadm --add /dev/md0 /dev/sdc' to initiate recovery and rebuild the array. Option A is incorrect because you cannot add a disk to an inactive array; you must first force the array to run. Option B is unnecessary; the system can be recovered without a live CD. Option C fails because stopping the array is impossible while the root filesystem is mounted, and reassembling without the missing disk will not succeed.

Answer

First run 'mdadm --manage /dev/md0 --add /dev/sdc', then 'mdadm --run /dev/md0'

Answer

Boot from a live CD, then run 'mdadm --assemble --scan' to reassemble

Answer

Run 'mdadm --stop /dev/md0', then 'mdadm --assemble /dev/md0 /dev/sda /dev/sdb /dev/sdc'

Question 14

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

Accepted Answer

Rebuild the initramfs using 'dracut --force --kver' with the correct kernel version. The 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)' error indicates the kernel cannot find or mount the root filesystem, often because the initramfs lacks the necessary drivers (e.g., ext4 module) for the new kernel. Rebuilding the initramfs with 'dracut --force --kver' ensures it includes the correct kernel modules for the newly compiled kernel, resolving the mismatch.

Answer

Run 'ldd /sbin/init' to check for missing libraries

Answer

Use 'mkinitrd' with the '--preload' option for ext4 module

Answer

Add 'root=/dev/sda2' to the kernel command line

Question 15

Which TWO statements about GRUB 2 are correct?

Accepted Answer

After modifying /etc/default/grub, the command update-grub must be run to regenerate grub.cfg.. After modifying /etc/default/grub, the update-grub command (which is a wrapper for grub-mkconfig) must be run to regenerate the /boot/grub/grub.cfg file. This ensures that changes to boot parameters, such as default timeout or kernel command-line options, are written into the actual configuration file that GRUB 2 reads at boot time.

Answer

GRUB 2 uses a configuration file named menu.lst.

Answer

The GRUB prompt can be accessed by pressing the 'e' key during boot.

Answer

The /etc/default/grub file is directly read by GRUB during boot.