EX200 Practice Test 31 — 15 Questions

Question 1

A user wants to set an environment variable named 'EDITOR' to the value '/usr/bin/vim' so that it is available in all future login sessions. Which file should the user add the export command to?

Accepted Answer

~/.bash_profile. The ~/.bash_profile file is executed for login shells, making it the correct place to set environment variables like EDITOR that should persist across all future login sessions. Adding 'export EDITOR=/usr/bin/vim' to this file ensures the variable is defined each time the user logs in.

Answer

~/.bash_logout

Answer

/etc/bashrc

Answer

~/.bashrc

Question 2

A partition /dev/sdc1 is formatted as ext4. The administrator needs to check the file system for errors without making any repairs. Which command should be used?

Accepted Answer

fsck -n /dev/sdc1. The `fsck -n` command checks the file system for errors without making any repairs, as the `-n` flag forces a non-interactive, read-only check. Since /dev/sdc1 is formatted as ext4, `fsck` automatically calls the appropriate ext4-specific tool (e2fsck) with the no-repair option. This matches the requirement to only check for errors without fixing them.

Answer

xfs_repair -n /dev/sdc1

Answer

fsck -y /dev/sdc1

Answer

e2fsck -p /dev/sdc1

Question 3

Which THREE are valid methods to configure network bonding in RHEL 9? (Choose exactly three.)

Accepted Answer

Using a configuration file in /etc/NetworkManager/system-connections/.. In RHEL 9, NetworkManager stores connection profiles in `/etc/NetworkManager/system-connections/`. You can manually create a bond configuration file in this directory with the proper key-value pairs (e.g., `type=bond`, `bond.options=mode=1,miimon=100`), and NetworkManager will read it on restart or reload. This is a valid method for configuring network bonding.

Answer

Using the teamd service.

Answer

Editing /etc/sysconfig/network-scripts/ifcfg-bond0 directly.

Question 4

An administrator wants to gracefully terminate a process with PID 12345. Which command should be used?

Accepted Answer

kill -TERM 12345. `kill -TERM` (or `kill -15`) sends the SIGTERM signal, which requests a process to terminate gracefully. This allows the process to perform cleanup tasks (e.g., closing files, releasing resources) before exiting, making it the standard way to stop a process politely.

Answer

kill -STOP 12345

Answer

kill -9 12345

Answer

kill -KILL 12345

Question 5

A new intern created a script to display the current user's home directory:

#!/bin/bash
echo "Home directory: $home"

The script outputs 'Home directory: ' with nothing after the colon. What is the most likely cause?

Accepted Answer

There is a typo: it should be $HOME, not $home.. Bash variable names are case-sensitive, so $home is a distinct variable from the standard $HOME environment variable. Since 'home' was never assigned, it expands to an empty string, producing the observed output. The correct reference is $HOME.

Answer

The HOME variable is not set in the environment.

Answer

The script is run with 'sh' instead of 'bash'.

Answer

The root user has no home directory.

Question 6

A junior administrator is tasked with setting up SELinux contexts on a Red Hat Enterprise Linux 9 server to allow Apache HTTPD to read and write to a custom directory /var/www/customcontent. The directory already exists and contains several files. The administrator has confirmed that the httpd service is running and SELinux is in enforcing mode. After changing the context to httpd_sys_content_t using chcon, the web server can read files but cannot write to the directory. The administrator needs to fix this without disabling SELinux or changing the mode to permissive. Which of the following is the correct next step?

Accepted Answer

Run restorecon -R -v /var/www/customcontent after setting the default context with semanage fcontext -a -t httpd_sys_rw_content_t '/var/www/customcontent(/.*)?'. The directory already has the httpd_sys_content_t type, which allows reading but not writing. To enable write access, the correct type is httpd_sys_rw_content_t. Option B correctly uses semanage fcontext to set the default context to this type and then runs restorecon to apply it persistently, ensuring Apache can both read and write.

Answer

Set the SELinux boolean httpd_enable_homedirs to on using setsebool.

Answer

Change the context to httpd_sys_content_t using chcon -R -t httpd_sys_content_t /var/www/customcontent

Answer

Run semanage fcontext -a -t httpd_sys_rw_content_t '/var/www/customcontent(/.*)?' without running restorecon.

Question 7

You are the system administrator for a small company. A developer, Alice, needs to restart the web server (httpd.service) on server 'web1.example.com' without being prompted for a password. She should also be able to run any command as root on that server, but only from the server itself (not remotely). Currently, Alice can SSH into the server using her SSH key, but when she runs 'sudo systemctl restart httpd', she is prompted for her password. You have verified that Alice is in the 'wheel' group. The sudoers file currently has the line '%wheel ALL=(ALL) ALL'. You want to modify sudoers to satisfy the requirement with minimal privilege. Which action should you take?

Accepted Answer

Add 'alice web1.example.com=(root) NOPASSWD: /usr/bin/systemctl restart httpd' to /etc/sudoers.d/alice.. It grants Alice passwordless sudo access specifically to the command `/usr/bin/systemctl restart httpd` on the host `web1.example.com` as root, meeting the requirement with minimal privilege. The `NOPASSWD:` tag is essential to bypass the password prompt, and the host restriction ensures the rule applies only when Alice is on that server.

Answer

Add 'alice web1.example.com=(root) NOPASSWD: ALL' to /etc/sudoers.d/alice.

Answer

Add 'alice web1.example.com=(root) /usr/bin/systemctl restart httpd' to /etc/sudoers.d/alice.

Answer

Change '%wheel ALL=(ALL) ALL' to '%wheel ALL=(ALL) NOPASSWD: ALL' in /etc/sudoers.

Question 8

A system has a disk that may be failing. Which tool can be used to check the health of a SATA disk using SMART monitoring?

Accepted Answer

smartctl. smartctl is the correct tool because it directly interfaces with the Self-Monitoring, Analysis, and Reporting Technology (SMART) built into modern SATA and ATA drives. It can query the drive's internal health metrics, such as reallocated sector counts and temperature, to predict potential failure. The other options do not access SMART data.

Answer

fsck

Answer

dd

Answer

badblocks

Question 9

A system administrator needs to create a new ext4 filesystem on /dev/sdb1 and mount it persistently at /data. Which set of commands should be used?

Accepted Answer

mkfs -t ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab. It creates the ext4 filesystem with `mkfs -t ext4 /dev/sdb1`, creates the mount point directory with `mkdir /data`, mounts the filesystem immediately with `mount /dev/sdb1 /data`, and then adds an entry to `/etc/fstab` using the correct format (device, mount point, filesystem type, options, dump, pass) to ensure the mount persists across reboots. The `&&` operator ensures each command only runs if the previous one succeeds, which is a safe practice for scripting this task.

Answer

mkfs.ext4 /dev/sdb1 && mount /dev/sdb1 /data

Answer

mkfs -t ext4 /dev/sdb1 && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab && mount /data

Answer

mkfs.ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && blkid /dev/sdb1 >> /etc/fstab

Question 10

A system administrator is troubleshooting a custom service called 'database.service' that fails intermittently. The service is a proprietary database that requires large amounts of memory. The administrator runs systemctl status database and sees 'Active: failed (Result: core-dump)' and the journal shows 'Out of memory: Killed process (database) total-vm:...' The server has 8GB RAM and 2 CPU cores. The service unit file does not contain any memory limits. The application is configured to use up to 4GB. The administrator suspects the systemd service is being killed by the OOM killer. Which action should the administrator take to prevent this issue?

Accepted Answer

Set OOMScoreAdjust=-1000 in the service unit file.. Setting OOMScoreAdjust=-1000 makes the systemd service less likely to be targeted by the OOM killer. The OOM killer selects processes based on a badness score; a lower score (down to -1000) reduces the likelihood of being killed. Since the service is already configured to use up to 4GB and the server has 8GB RAM, adjusting the OOM score is the targeted fix without disabling kernel protections or over-allocating resources.

Answer

Set MemoryMax=6G in the service unit file.

Answer

Modify kernel parameters to disable the OOM killer.

Answer

Increase swap space to 16GB.

Question 11

A user is unable to log in via SSH. The administrator checks /var/log/secure and sees 'Authentication refused: bad ownership or modes' for the user's home directory. What is the most likely cause?

Accepted Answer

The user's home directory is owned by root. The error 'Authentication refused: bad ownership or modes' includes the path of the offending file. When the log message references the user's home directory, it means the home directory itself has incorrect ownership or permissions. SSH's StrictModes requires the home directory to be owned by the user and not writable by group or others. If the home directory is owned by root, sshd refuses authentication. The correct answer is D.

Answer

The sshd service is not running

Answer

The SELinux context is wrong

Answer

The .ssh/authorized_keys file has incorrect permissions

Question 12

Refer to the exhibit. What is the most likely cause of the httpd service failure?

Accepted Answer

The Apache configuration has a syntax error.. The most likely cause of the httpd service failing to start is a configuration syntax error (option B). When the Apache configuration contains an invalid directive or syntax mistake, `httpd` will refuse to start and report the error via `apachectl configtest` or `systemctl start httpd`. A missing document root may cause a warning but does not prevent startup; incorrect SELinux context leads to 403 errors but does not stop the service; and a disabled service only affects boot-time startup, not manual starts.

Answer

The httpd service is disabled.

Answer

The /var/www/html directory does not exist.

Answer

SELinux context on /var/www/html/index.html is incorrect.

Question 13

Which TWO commands can list all groups a user belongs to? (Choose exactly 2)

Accepted Answer

id -nG. Option A, `id -nG`, is correct because it prints the names of all groups the specified user is a member of, including both the primary group and supplementary groups, using the `-n` flag to show names instead of numeric GIDs and `-G` to list all group memberships. Option E, `groups`, is correct because it displays the groups a user belongs to, defaulting to the current user or accepting a username argument, and it reads from the same system group database to show all memberships. Option B, `cat /etc/group | grep user`, is not reliable because it only matches the literal string 'user' in the group file and may miss memberships or match unintended entries, and it does not handle network-based group sources. Option C, `usermod -g user`, is incorrect because it modifies a user's primary group rather than listing group memberships. Option D, `getent group user`, is incorrect because it queries the group database for a group named 'user' and lists that group's members, not all groups a user belongs to.

Answer

cat /etc/group | grep user

Answer

usermod -g user

Answer

getent group user

Question 14

Which TWO commands can mount an ISO file /tmp/rhel.iso to /mnt/iso?

Accepted Answer

mount -o loop /tmp/rhel.iso /mnt/iso. Option A is correct because `mount -o loop /tmp/rhel.iso /mnt/iso` uses the loop option to associate the ISO file with a loop device and mount it; on modern Linux, mount auto-detects the ISO9660 filesystem, so no explicit type is required. Option C is also correct because `mount -t iso9660 -o loop /tmp/rhel.iso /mnt/iso` explicitly specifies the ISO9660 filesystem type while still using the loop option, which is the traditional and fully explicit way to mount an ISO image. Option B is wrong because `isomount` is not a standard Linux command. Option D is wrong as written because `losetup /tmp/rhel.iso` without `-f` does not reliably create/attach a loop device and the chained mount assumes /dev/loop0, which may not be the device assigned. Option E is wrong because `mount /tmp/rhel.iso /mnt/iso` lacks the loop option and will fail to mount a regular file as a block device.

Answer

isomount /tmp/rhel.iso /mnt/iso

Answer

losetup /tmp/rhel.iso && mount /dev/loop0 /mnt/iso

Answer

mount /tmp/rhel.iso /mnt/iso

Question 15

Which THREE commands can be used to monitor real-time process status and update the display every 2 seconds? (Choose three.)

Accepted Answer

htop. Option A, htop, is correct because it is an interactive real-time process viewer that continuously refreshes its display (by default every second, and its refresh interval is configurable), so it can monitor process status in real time. Option B, top -d 2, is correct because top is the classic real-time process monitor and the -d 2 flag explicitly sets the screen update delay to 2 seconds. Option D, watch -n 2 ps aux, is correct because watch repeatedly executes the given command at a fixed interval, and -n 2 makes it rerun ps aux every 2 seconds, producing a refreshed process listing. Option C, ps aux, is not correct because ps is a one-shot snapshot command that prints process information once and exits, with no continuous refresh. Option E, at 2, is not correct because at is a job-scheduling utility for running commands at a specified future time, not a real-time process monitoring tool.

Answer

ps aux

Answer

at 2