EX200 Practice Test 4 — 25 Questions

Question 1

A junior system administrator configures rsyslog on a RHEL 9 server to forward logs to a remote centralized log server. They add the line *.* @192.168.1.100:514 to /etc/rsyslog.conf and restart rsyslog with systemctl restart rsyslog. Local logging works fine, but the remote server does not receive any logs. The administrator checks the local firewall and confirms that UDP port 514 is open outbound. They also verify network connectivity using nc. What is the most likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The SELinux boolean rsyslog_remote is disabled, blocking outbound syslog.. On RHEL 9, SELinux enforces a targeted policy that blocks rsyslog from making outbound network connections by default. The boolean `rsyslog_remote` controls this behavior; when disabled, SELinux denies the outbound syslog traffic even though the local firewall allows it. The administrator must enable this boolean with `setsebool -P rsyslog_remote on` to allow rsyslog to forward logs via UDP or TCP.

Answer

The systemd unit for rsyslog is masked, preventing it from running.

Answer

The remote rsyslog server is not listening on UDP port 514.

Answer

The configuration should use @@ for TCP instead of @ for UDP.

Question 2

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

Accepted Answer

Another process is already bound to port 22.. The error message in the exhibit indicates that the sshd service failed to start because port 22 is already in use. This is a classic port conflict, where another process (e.g., another SSH daemon, a web server misconfigured to use port 22, or a leftover process) has bound to the same TCP port. The system log or `ss -tlnp` would show the PID and name of the conflicting process, confirming that port 22 is unavailable for the new sshd instance.

Answer

The sshd service is not enabled.

Answer

SELinux is blocking the service.

Answer

The /etc/ssh/sshd_config file is missing.

Question 3

An administrator needs to configure a service to start automatically at boot and also start it immediately without rebooting. Which single command accomplishes both tasks?

Accepted Answer

systemctl enable --now httpd.service. `systemctl enable --now httpd.service` combines the `enable` action (creating symlinks for automatic start at boot) with the `start` action (immediately launching the service) in a single command. This is the precise method in systemd to achieve both goals without rebooting.

Answer

systemctl start httpd.service

Answer

systemctl enable httpd.service

Answer

systemctl reenable httpd.service

Question 4

Which TWO commands are valid for resizing an XFS file system? (Choose exactly two.)

Accepted Answer

xfs_growfs /mnt. `xfs_growfs` is the dedicated command for resizing (growing) an XFS file system while it is mounted. It expands the file system to fill the available space in the underlying device or logical volume, making it the primary tool for XFS resizing operations.

Answer

xfs_admin -L /mnt

Answer

resize2fs /dev/sda1

Answer

xfs_repair /dev/sda1

Question 5

An administrator wants to change the default systemd target to multi-user.target. Which three steps are part of a correct procedure? (Choose three.)

Accepted Answer

systemctl isolate multi-user.target. `systemctl isolate multi-user.target` immediately switches the current systemd target to multi-user.target, which is the correct way to change the active target at runtime without a reboot. This command stops all units not required by the new target and starts those that are, effectively changing the system's operational state.

Answer

systemctl enable multi-user.target

Answer

systemctl start multi-user.target

Question 6

Consider the script in the exhibit. The script is run in a directory containing 'a.txt' and 'b.txt' but also has a subdirectory 'backup' with .txt files. What will be the output?

Accepted Answer

Line counts for 'a.txt' and 'b.txt' only. The script uses `for i in *.txt`, which by default only matches .txt files in the current directory, not in subdirectories. Since 'a.txt' and 'b.txt' are in the current directory, the loop iterates over them and runs `wc -l` on each, outputting their line counts. The 'backup' subdirectory is not traversed because the glob pattern does not include paths with directories.

Answer

An error because the for loop cannot iterate over files with spaces

Answer

Line counts for .txt files in 'backup' only

Answer

Line counts for all .txt files including those in 'backup'

Question 7

A system administrator needs to create a file system on a new 10GB partition /dev/sdb1 for use with a database that requires high reliability and supports snapshots. Which file system type should be chosen?

Accepted Answer

xfs. XFS is the correct choice because it is a high-performance, 64-bit journaling file system that supports snapshots via LVM or external tools, and is designed for large files and partitions. For a database requiring high reliability and snapshot capabilities, XFS provides robust data integrity features and is the default file system in Red Hat Enterprise Linux 8 and later, making it the recommended option for this scenario.

Answer

ext4

Answer

vfat

Answer

btrfs

Question 8

A user reports that they cannot create files in their home directory. The administrator checks permissions and sees drwxr-xr-x. What is the likely cause?

Accepted Answer

The user is not the owner of the directory. The permissions `drwxr-xr-x` mean the owner has read, write, and execute (rwx) access, while group and others have only read and execute (r-x). Since the user cannot create files (which requires write permission), the user must not be the owner of the directory. Only the owner (or root) can write to it, so the likely cause is that the user is not the owner.

Answer

The directory has the sticky bit set

Answer

The filesystem is read-only

Answer

The user is not in the group

Question 9

A container named 'web1' was created and ran briefly before exiting with status 0. The administrator needs to restart it and attach to the running container's console. Which command should be used?

Accepted Answer

podman start web1 && podman attach web1. `podman start web1` restarts the existing container that exited with status 0, and `podman attach web1` connects the current terminal to the container's main process console. The `&&` ensures the attach runs only after the container is successfully started, allowing the administrator to interact with the running container's console.

Answer

podman run --name web1 -it registry.access.redhat.com/ubi8/httpd-24

Answer

podman start web1

Answer

podman restart web1 && podman attach web1

Question 10

Refer to the exhibit. The /proc/mdstat output shows a RAID1 array with two devices. One of the disks (/dev/sda1) fails. Which sequence of commands would be used to remove the failed disk and add a new replacement disk /dev/sdc1?

Accepted Answer

mdadm /dev/md0 --fail /dev/sda1; mdadm /dev/md0 --remove /dev/sda1; mdadm /dev/md0 --add /dev/sdc1. It uses the proper mdadm syntax with the device name immediately after the command, followed by the action and the disk. The --fail flag marks the disk as faulty, --remove removes it from the array, and --add adds the new replacement disk. This sequence ensures the array remains in a degraded state before safely replacing the failed component.

Answer

mdadm --fail /dev/md0 /dev/sda1; mdadm --remove /dev/md0 /dev/sda1; mdadm --add /dev/md0 /dev/sdc1

Answer

mdadm /dev/md0 --set-faulty /dev/sda1; mdadm /dev/md0 --remove /dev/sda1; mdadm /dev/md0 --add /dev/sdc1

Answer

mdadm /dev/md0 --remove /dev/sda1; mdadm /dev/md0 --add /dev/sdc1

Answer

mdadm /dev/md0 --replace /dev/sda1 --with /dev/sdc1

Question 11

A server has a software RAID 5 array /dev/md0. One of its disks fails. The administrator wants to replace it without rebooting. Which command should be used to mark the disk as failed?

Accepted Answer

mdadm --fail /dev/md0 /dev/sdb. The correct command to mark a disk as failed in a software RAID array without rebooting is `mdadm --fail /dev/md0 /dev/sdb`. This command tells the md driver to mark the specified disk as faulty, which triggers the RAID 5 array to degrade and allows the failed disk to be removed and replaced while the system remains online.

Answer

mdadm --fault /dev/md0 /dev/sdb

Answer

echo faulty > /sys/block/md0/md/dev-sdb/state

Answer

mdadm --set-faulty /dev/md0 /dev/sdb

Question 12

An administrator needs to add a 1GB swap partition on /dev/sdd1. Which series of commands accomplishes this?

Accepted Answer

fdisk /dev/sdd, create partition, then mkswap /dev/sdd1, swapon /dev/sdd1, and add to /etc/fstab.. It includes all necessary steps: first create the partition with fdisk (since /dev/sdd1 does not exist yet), then format it as swap with mkswap, activate it with swapon, and finally add an entry to /etc/fstab to ensure persistence across reboots. The other options omit the critical partition creation step or fail to make the swap permanent.

Answer

mkswap /dev/sdd1 && echo '/dev/sdd1 swap swap defaults 0 0' >> /etc/fstab

Answer

mkfs.swap /dev/sdd1 && swapon /dev/sdd1

Answer

mkswap /dev/sdd1 && swapon /dev/sdd1

Question 13

A server has an LVM volume group vg01 with a physical volume /dev/sdb. The administrator wants to move all physical extents from /dev/sdb to /dev/sdd which is also in the same volume group. Which command sequence is correct?

Accepted Answer

pvmove /dev/sdb; vgreduce vg01 /dev/sdb. The correct sequence is to first use `pvmove /dev/sdb` to relocate all physical extents from /dev/sdb to other physical volumes in the same volume group (vg01), and then use `vgreduce vg01 /dev/sdb` to remove the now-empty physical volume from the volume group. This ensures no data loss and that the volume group metadata is properly updated.

Answer

vgreduce vg01 /dev/sdb; pvmove

Answer

pvmove /dev/sdb; pvremove /dev/sdb

Answer

pvmove /dev/sdb /dev/sdd

Question 14

A system fails to boot and drops into an emergency shell. The administrator suspects a misconfigured /etc/fstab. Which command should be used to determine which filesystem is causing the boot issue?

Accepted Answer

journalctl -xb -p err. When a system fails to boot due to a misconfigured /etc/fstab, the emergency shell is entered. The `journalctl -xb -p err` command displays the systemd journal from the current boot (`-b`) with extended information (`-x`) and filters for error-level messages (`-p err`). This will show the exact mount failure and the offending filesystem entry, making it the correct diagnostic tool.

Answer

systemctl status local-fs.target

Answer

fsck -A

Answer

mount -a

Question 15

Refer to the exhibit. Which entry is most likely to cause the system to fail to boot if the NFS server is unavailable?

Accepted Answer

The fourth entry (/mnt). The /mnt entry in /etc/fstab is configured with the default mount options, which include the _netdev option being absent. Without _netdev, the system will attempt to mount the NFS filesystem during the boot process before the network is fully operational. If the NFS server is unavailable, the mount will fail, and because the default mount behavior for non-root filesystems in /etc/fstab is to cause a boot failure if the mount fails (unless the 'nofail' option is specified), the system will drop into emergency mode and fail to complete the boot process.

Answer

The third entry (/home)

Answer

The second entry (/boot)

Answer

The first entry (/)

Question 16

An administrator is tasked with deploying a containerized application on a Red Hat Enterprise Linux 8 server that is part of a high-security environment. The application must run as a non-root user inside the container. The container image is based on Red Hat Universal Base Image (UBI) and exposes port 443 for HTTPS. The administrator needs to ensure that the container can be restarted automatically if it crashes and that the application logs are persisted on the host in /var/log/app. The application requires a configuration file that is generated dynamically at startup and must be accessible to the container. The administrator has created a systemd service file for the container but wants to use Podman's built-in features to manage the container. Which approach meets all requirements?

Accepted Answer

Run the container with 'podman run --restart=always -v /var/log/app:/var/log -p 443:443 myapp' and rely on the container's restart policy.. Podman's built-in restart policy (`--restart=always`) ensures the container restarts automatically after a crash without requiring systemd. The volume mount persists logs at /var/log/app on the host, and the port mapping exposes port 443. This approach uses Podman's native features as desired, meeting all requirements. Option A relies on a systemd service generated by Podman, which shifts management back to systemd instead of using Podman's built-in restart capability. Option B uses an invalid command. Option D uses `--restart=on-failure`, which only restarts on non-zero exit codes and may miss other crash scenarios.

Answer

Create a systemd service file using 'podman generate systemd' on a running container, then enable the service with 'systemctl enable --now container-myapp'. The container should be started with '--restart=always' and appropriate volume and port mappings.

Answer

Create a 'podman service' unit using 'podman service create' to manage the container with automatic restart and boot-start.

Answer

Use 'podman create --restart=on-failure -v /var/log/app:/var/log -p 443:443 myapp' and then start it with 'podman start'.

Question 17

An administrator writes a script to check disk usage and send an alert if usage exceeds 80%. The script uses 'df -h /' and parses the output. To maintain portability and avoid common pitfalls, which approach is recommended?

Accepted Answer

Use 'df / | awk 'NR==2 {print $5}' | tr -d '%'. It uses `df /` (without `-h`) to produce a stable, machine-parseable output where the fifth field (`$5`) is always the percentage used, and `awk` reliably extracts it. The `tr -d '%'` removes the percent sign for numeric comparison. This approach avoids the portability issues of parsing human-readable output from `df -h`, which can vary in column spacing and ordering across different Unix/Linux systems.

Answer

Use 'df -h / | tail -1 | sed 's/.* //' | tr -d '%'

Answer

Use 'df -h / | tail -1 | cut -d' ' -f5'

Answer

Use 'df -h / | grep -oP '\d+%'

Question 18

Refer to the exhibit. After mounting /dev/sdb1 with the noexec option, a script located at /mnt/data/test.file cannot be executed. What change will allow execution while maintaining security?

Accepted Answer

Change the mount option to exec in /etc/fstab and remount. The noexec mount option prevents execution of any binaries or scripts on the filesystem, regardless of file permissions. To allow execution while maintaining security, you must change the mount option to exec in /etc/fstab and remount the filesystem (e.g., mount -o remount,exec /mnt/data). This approach preserves other mount options and avoids the security risks of removing noexec globally.

Answer

Copy the script to /tmp and run from there

Answer

Use chmod +x /mnt/data/test.file

Answer

Remount without noexec and add setuid bit

Question 19

Refer to the exhibit. The administrator wants to add an additional 5GB to the /mnt/data filesystem. There is no unpartitioned space on /dev/sdb. Which is the correct procedure?

Accepted Answer

Use fdisk to delete and recreate /dev/sdb1 with larger size, run partprobe, then xfs_growfs /mnt/data.. The filesystem on /mnt/data is XFS (as shown in the exhibit), and XFS cannot be shrunk; it can only be grown. Since there is no unpartitioned space on /dev/sdb, the partition itself must be resized. The correct procedure is to delete and recreate the partition with a larger size using fdisk, inform the kernel of the change with partprobe, and then grow the XFS filesystem with xfs_growfs /mnt/data.

Answer

Use resize2fs /dev/sdb1 to expand filesystem.

Answer

Add a new disk, create a physical volume, extend volume group, and extend logical volume.

Answer

Use fdisk to delete and recreate /dev/sdb1 with larger size, then mount.

Question 20

An administrator needs to compress a directory containing subdirectories and files into a single archive file, with maximum compression, and exclude all '*.tmp' files. Which command should be used?

Accepted Answer

tar -cjvf archive.tar.bz2 --exclude='*.tmp' /path/to/dir. The question specifies 'maximum compression'. Among common tar compression methods, bzip2 (via the -j flag) typically provides better compression ratios than gzip (-z), though it is slower. Option C uses `tar -cjvf` with the `--exclude` option placed correctly before the source directory, which is the proper syntax for tar exclusions. This command creates a .tar.bz2 archive with maximum compression while excluding all *.tmp files. Option A uses gzip, which offers faster compression but lower ratios, making it incorrect for 'maximum compression'. Options B and D also fail: B has incorrect syntax (--exclude after the directory), and D omits the exclude option entirely.

Answer

tar -czvf archive.tar.gz --exclude='*.tmp' /path/to/dir

Answer

tar -czvf archive.tar.gz /path/to/dir --exclude='*.tmp'

Answer

tar -czvf archive.tar.gz /path/to/dir