EX200 Practice Test 2 — 30 Questions

Question 1

A filesystem is reported as 'read-only' after a system crash. The admin runs fsck and sees 'clean' status. What is the most likely reason it remains read-only?

Accepted Answer

The filesystem is XFS, and fsck does not repair XFS.. If fsck reports 'clean', it means no errors were found in the filesystem's journal, so option D is incorrect. Option C is correct because XFS filesystems cannot be repaired by fsck; they require xfs_repair. Running fsck on an XFS filesystem simply reports the clean flag without performing a real check, leaving the kernel to enforce read-only status if any issues persist.

Answer

fsck cannot fix errors on ext4 filesystems.

Answer

The filesystem is still mounted; fsck cannot fix it while mounted.

Answer

fsck detected errors but did not fix them automatically.

Question 2

A script needs to be run at system boot for a specific user. Which method ensures the script runs with that user's environment?

Accepted Answer

Create a systemd user unit in ~/.config/systemd/user/. Systemd user units, placed in ~/.config/systemd/user/, are executed in the user's own session context, inheriting the user's environment variables, PATH, and D-Bus session. This ensures the script runs with the specific user's environment at boot, as systemd starts the user manager (systemd --user) early in the boot process for each enabled user.

Answer

Place the script in /etc/rc.d/rc.local

Answer

Add an entry to ~/.xprofile

Answer

Add the script to the user's crontab with @reboot

Question 3

A system administrator is troubleshooting a container that fails to start with the error: 'Error: cannot start container: listen tcp4 :80: bind: address already in use'. The container is intended to serve HTTP traffic on port 80. What is the most appropriate first step to resolve this issue?

Accepted Answer

Check which process is using port 80 and either stop that process or use a different host port. The error 'address already in use' indicates that port 80 on the host is already occupied by another process. The correct first step is to identify that process using commands like `ss -tlnp` or `lsof -i :80` and either stop it or map the container to a different host port (e.g., `-p 8080:80`). This directly resolves the binding conflict without risking data loss or unintended behavior.

Answer

Add --force to the podman run command

Answer

Add --replace to the podman run command

Answer

Use --net=host to bypass the port mapping

Question 4

Refer to the exhibit. A user named 'carol' has been added to the system with the command useradd -G wheel carol. Which line in /etc/group will confirm that carol is now a member of the wheel group?

Accepted Answer

wheel:x:10:root,alice,bob,carol. The `useradd -G wheel carol` command adds 'carol' to the supplementary group 'wheel', and the `/etc/group` file lists supplementary members as a comma-separated list with no trailing comma. The line `wheel:x:10:root,alice,bob,carol` shows 'carol' appended after the existing members, which matches the expected format.

Answer

wheel:x:10:carol,root,alice,bob

Answer

wheel:x:10:root,alice,bob,carol,

Answer

wheel:x:10:root,alice,bob carol

Question 5

A developer runs the script shown in the exhibit and always sees 'Success' printed, even when the previous command fails. What is the most likely cause?

Accepted Answer

The $? variable captures the exit status of the [[ command, not the intended command. The `[[ ]]` conditional construct is a shell keyword that itself produces an exit status. When `$?` is checked immediately after `[[ ]]`, it captures the exit status of the `[[ ]]` evaluation (which is 0 if the condition is true, 1 if false), not the exit status of the command that was run before the `[[ ]]`. Since the developer always sees 'Success' printed, the `[[ ]]` condition must be evaluating to true (exit status 0), causing `$?` to be 0 and the script to always take the success path, regardless of the actual previous command's result.

Answer

The [[ ]] syntax always evaluates to true

Answer

The $? variable is only set after external commands, not builtins

Answer

The $? variable always returns 0 in a conditional

Question 6

A new employee named asmith needs a user account with a home directory and a specific UID of 1500. Which command accomplishes this?

Accepted Answer

useradd -m -u 1500 asmith. `useradd -m -u 1500 asmith` creates the user asmith with a home directory (via `-m`) and assigns a specific UID of 1500 (via `-u`). The `-m` flag ensures the home directory is created if it does not exist, which is required by the question.

Answer

adduser -uid 1500 asmith

Answer

useradd -h /home/asmith -u 1500 asmith

Answer

useradd -d /home/asmith -U 1500 asmith

Question 7

An administrator wants to ensure that any new user accounts created on the system have a default primary group matching the username. What change is needed?

Accepted Answer

Set USERGROUPS_ENAB to yes in /etc/login.defs. Setting USERGROUPS_ENAB to yes in /etc/login.defs instructs the useradd command to automatically create a private group with the same name as the new user and assign it as the user's primary group. This is the default behavior in Red Hat Enterprise Linux and ensures that each new user has a matching primary group without manual intervention.

Answer

Set GROUP to same name in /etc/default/useradd

Answer

Set USERGROUPS_ENAB to no; then create user with -g

Answer

Set CREATE_HOME to yes in /etc/login.defs

Question 8

A system administrator needs to change the primary group of an existing user to a group that already exists. Which command should be used?

Accepted Answer

usermod -g existinggroup username. The `usermod -g` command changes the primary group of an existing user to a specified group that already exists on the system. The `-g` option sets the initial login group (GID) for the user, which must be a valid group name or GID from `/etc/group`.

Answer

groupmod -g existinggroup username

Answer

usermod -p existinggroup username

Answer

usermod -G existinggroup username

Question 9

A server has been compromised, and the administrator suspects an unauthorized user account may have been created. Which file should be examined to list all local user accounts?

Accepted Answer

/etc/passwd. The /etc/passwd file is the primary local user account database on Linux systems, listing all user accounts with fields such as username, UID, GID, GECOS, home directory, and login shell. Examining this file reveals every local user account, including any unauthorized ones that may have been created, because each account must have an entry here to be recognized by the system.

Answer

/etc/shadow

Answer

/etc/shells

Answer

/etc/login.defs

Question 10

An administrator needs to schedule a script to run every Monday, Wednesday, and Friday at 2:30 PM. Which cron expression should be used?

Accepted Answer

30 14 * * 1,3,5. Cron uses five fields (minute, hour, day-of-month, month, day-of-week). 2:30 PM is 14:30 in 24-hour format, so minute=30 and hour=14. The day-of-week field uses 0-7 (0 and 7 = Sunday), with Monday=1, Wednesday=3, Friday=5. The asterisks for day-of-month and month mean 'every day' and 'every month', so the expression `30 14 * * 1,3,5` runs the script at 2:30 PM on Monday, Wednesday, and Friday.

Answer

30 14 * * 1-5

Answer

14 30 * * 1,3,5

Answer

30 14 * * 0,2,4

Question 11

A systems administrator installs a custom hardware device driver kernel module named 'mydevice' on a RHEL 9 system. The module is built and placed in /lib/modules/$(uname -r)/extra/. The administrator loads it manually with modprobe mydevice and it works. However, after a system reboot, the module is not loaded. The administrator checks that the device is present at boot time. Which step should be taken to ensure the module loads automatically at boot?

Accepted Answer

Run 'echo mydevice > /etc/modules-load.d/mydevice.conf'. Writing the module name to a file in /etc/modules-load.d/ ensures systemd loads the module automatically at boot. The modules-load.d mechanism is the standard RHEL 9 method for specifying kernel modules to be loaded early in the boot process, before the root filesystem is fully available.

Answer

Add the line 'install mydevice /sbin/modprobe --ignore-install mydevice' to /etc/modprobe.d/load.conf

Answer

Rebuild the initramfs with 'dracut --force --add mydevice'

Answer

Add the line 'load mydevice' to /etc/rc.local and ensure rc.local is executable.

Question 12

Which TWO commands can be used to add a user to a secondary group without removing existing supplementary group memberships? (Choose exactly 2)

Accepted Answer

usermod -aG group user. `usermod -aG` appends the user to the specified supplementary group(s) without affecting any existing supplementary group memberships. The `-a` flag (append) must be used with `-G` to avoid overwriting the current list of supplementary groups. This is the standard method in Red Hat Enterprise Linux for adding a user to an additional group while preserving all other group memberships.

Answer

usermod -AG group user

Answer

adduser user group

Answer

groupadd -a user group

Question 13

A developer wrote a shell script that is intended to back up log files by copying all .log files from /var/log/myapp to /backup/logs. The script runs daily via cron but the backup folder is empty. The script contains the following line: `cp /var/log/myapp/*.log /backup/logs/`. What is the most likely reason the backup fails?

Accepted Answer

No .log files exist in /var/log/myapp at the time of script execution, causing the glob to match nothing.. The glob pattern `*.log` in the `cp` command is expanded by the shell at the time the script runs. If no `.log` files exist in `/var/log/myapp` when the cron job executes, the shell passes the literal string `*.log` to `cp`, which then fails with a 'No such file or directory' error (or, depending on shell settings, may silently do nothing). This is a common issue when log rotation or cleanup removes files before the backup runs.

Answer

The PATH variable in cron is not set, so cp cannot be found.

Answer

The script does not have execute permission for the user running cron.

Answer

The cron job is not enabled because the crontab syntax is incorrect.

Question 14

The administrator attempts to run 'xfs_growfs /dev/vg00/lvol1' but receives an error. What is the most likely cause?

Accepted Answer

The logical volume is not mounted. The `xfs_growfs` command requires the XFS filesystem to be mounted in order to resize it. If the logical volume `/dev/vg00/lvol1` is not mounted, the kernel cannot access the filesystem's superblock and allocation group information, causing the command to fail with an error such as 'XFS filesystem not mounted' or 'No such file or directory'.

Answer

The file system is not XFS

Answer

Unmet dependencies

Answer

The volume group is full

Question 15

An administrator wants to add 20GB of additional space to the root filesystem. The volume group vg01 has no free extents. Which action should be taken first?

Accepted Answer

Attach a new disk, create a physical volume on it, add it to vg01 with vgextend, then extend vg01-root. To extend the root filesystem when the volume group has no free extents, you must first add a new physical volume to the volume group. This involves attaching a new disk, creating a physical volume on it with `pvcreate`, adding it to vg01 with `vgextend`, and then using `lvextend` followed by `resize2fs` (or `xfs_growfs` for XFS) to extend the logical volume and filesystem. This sequence ensures the volume group has available extents before extending the logical volume.

Answer

Shrink the logical volume vg01-data and then extend vg01-root

Answer

Run vgextend vg01 /dev/sdc (assuming /dev/sdc is a new disk) but this command requires the PV to be created first

Answer

Use lvextend to extend the root logical volume into the free space of sdb1

Question 16

Refer to the exhibit. An administrator wants to create an LVM logical volume using /dev/sdb3. What is the first step to complete this task?

Accepted Answer

Create a logical volume with lvcreate -L 10G -n lv01 vg01. Based on the exhibit, /dev/sdb3 is already initialized as a physical volume and belongs to a volume group. Therefore, the first step to create a logical volume is to use lvcreate directly, as the PV and VG are already in place. Option B is incorrect because pvcreate is not needed when the partition is already a PV.

Answer

Format the partition with mkfs.ext4 /dev/sdb3

Answer

Create a physical volume with pvcreate /dev/sdb3

Answer

Create a volume group with vgcreate vg01 /dev/sdb3

Question 17

A RHEL 9 system has a second disk /dev/sdb that needs to be partitioned with a single partition using all space, formatted with XFS, and mounted persistently at /data. The administrator uses fdisk to create the partition /dev/sdb1. Which filesystem creation command should be used?

Accepted Answer

mkfs.xfs /dev/sdb1. The correct command is mkfs.xfs /dev/sdb1 because the question specifies that the partition must be formatted with XFS. The mkfs.xfs command is the dedicated tool for creating an XFS filesystem on a block device. It directly invokes the mkfs.xfs utility, which writes the XFS superblock and metadata structures to the partition.

Answer

mke2fs /dev/sdb1

Answer

mkfs -t ext4 /dev/sdb1

Answer

mkfs.ext4 /dev/sdb1

Question 18

Refer to the exhibit. The backup script runs every 5 minutes but generates errors. What is the most likely cause?

Accepted Answer

The script is not executable.. The cron job fails because the script lacks execute permissions. Cron requires that scripts specified in crontab entries have the executable bit set (chmod +x) for the user under whose crontab the job runs. Without this, the cron daemon cannot spawn the script as a process, resulting in errors.

Answer

The script is owned by root.

Answer

The cron daemon is not running.

Answer

The script uses absolute paths.

Question 19

An administrator wants to add the two 2G disks (sdc and sdd) as physical volumes, extend the 'data' logical volume in volume group 'vg' by 2G, and grow the filesystem. Which sequence of commands should be used?

Accepted Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvextend -L +2G /dev/vg/lv_data; xfs_growfs /data. It follows the correct sequence: create physical volumes on both disks, extend the volume group with both disks in a single command, extend the logical volume by exactly 2G using the `+` sign, and then grow the XFS filesystem using `xfs_growfs` with the mount point `/data`. The `+` in `lvextend -L +2G` is critical to add 2G rather than resize to 2G total, and `xfs_growfs` requires the mount point (or a block device) for XFS filesystems.

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvresize -L 2G /dev/vg/lv_data; xfs_growfs /data

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvextend -L +2G /dev/vg/lv_data; resize2fs /dev/vg/lv_data

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc; vgextend vg /dev/sdd; lvextend -L +2G /dev/vg/lv_data; xfs_growfs /dev/vg/lv_data

Question 20

A junior administrator configured a new network interface (ens224) with a static IP address using a configuration file in /etc/sysconfig/network-scripts/ifcfg-ens224. After restarting the network service, the interface comes up but does not get the IP address. The administrator runs 'ip addr show ens224' and sees no IP address assigned. The interface is listed as DOWN. The administrator then runs 'ifup ens224' manually, which succeeds, and the IP address appears. What is the most likely cause?

Accepted Answer

The ONBOOT directive is set to no in the ifcfg file.. The ONBOOT directive controls whether the interface is automatically brought up at system boot. When set to 'no', the interface configuration file is read but the interface remains DOWN after a network service restart, requiring manual intervention via 'ifup'. The junior administrator's observation that 'ifup ens224' succeeds confirms the configuration is valid, but the interface fails to activate automatically due to ONBOOT=no.

Answer

The network service is not enabled to start at boot.

Answer

The interface name does not match the device file.

Answer

There is a conflict with NetworkManager managing the interface.