EX200 Practice Test 13 — 15 Questions

Question 1

A company runs a critical web application in a container on a Red Hat Enterprise Linux 9 server. The container is started via a systemd service called 'webapp.service'. The service unit file was generated using 'podman generate systemd --new --name webapp'. Recently, after a kernel update and reboot, the service fails to start the container. The administrator runs 'systemctl status webapp.service' and sees 'Active: failed (Result: exit-code)' and 'Process: 1234 ExecStart=/usr/bin/podman run ... (code=exited, status=125)'. The administrator also checks 'journalctl -u webapp.service' and sees: 'Error: unable to start container: container create failed: OCI runtime error: container_linux.go:380: starting container process caused: exec: "/usr/bin/app.sh": stat /usr/bin/app.sh: no such file or directory'. The container image was built locally using a Containerfile that includes 'COPY app.sh /usr/bin/app.sh'. The administrator verifies the image is present locally. What should the administrator do to resolve this issue?

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

Accepted Answer

Rebuild the container image using 'podman build -t webapp .' to ensure the app.sh file is included, then restart the service.. The error indicates that the container image is missing the `/usr/bin/app.sh` file, even though the `COPY` instruction was in the Containerfile. The most likely cause is that the image was built before the `app.sh` script was added to the build context, or the build was incomplete. Rebuilding the image with `podman build -t webapp .` ensures the file is properly included in the image layers, resolving the OCI runtime error.

Answer

Disable SELinux with setenforce 0 and restart the service.

Answer

Remove the systemd service and regenerate it with 'podman generate systemd --new --name webapp'.

Answer

Manually create the /usr/bin/app.sh file inside the container using podman exec.

Question 2

Based on the exhibit, which command should be used to start the container named 'mycontainer'?

Accepted Answer

podman start mycontainer. The correct command to start an existing but stopped container is 'podman start mycontainer'. 'podman start' resumes a container that has been created (via 'podman create') or previously stopped, without creating a new instance. Option D is correct because it directly addresses the requirement to start the container named 'mycontainer' that already exists.

Answer

podman attach mycontainer

Answer

podman restart mycontainer

Answer

podman run mycontainer

Question 3

A cron job fails to run. Which command should the administrator use to verify the cron daemon is active?

Accepted Answer

systemctl status crond. On RHEL-based systems (including Red Hat Enterprise Linux, CentOS, and Fedora), the cron daemon is named `crond`, not `cron`. The `systemctl status crond` command checks whether the `crond` service is active, enabled, and running. This is the correct method for verifying the cron daemon's status on systems using systemd.

Answer

systemctl status cron

Answer

systemctl list-units --type=service

Answer

service crond status

Question 4

A user wants to run a container that will restart automatically unless explicitly stopped by the administrator. Which podman run option should be used?

Accepted Answer

--restart=unless-stopped. The `--restart=unless-stopped` policy ensures the container restarts automatically whenever it exits, unless the administrator explicitly stops it with `podman stop`. This matches the requirement exactly: the container will keep restarting even after system reboots or crashes, but will not restart if the admin manually stops it. The other policies either do not restart on manual stop (`always`) or only restart on non-zero exit codes (`on-failure`).

Answer

--restart=on-failure

Answer

--restart=always

Answer

--restart=no

Question 5

An administrator wants to add an additional swap partition of 2GB on device /dev/sdb1. Which set of commands should be used to enable swap and make it persistent across reboots?

Accepted Answer

mkswap /dev/sdb1; swapon /dev/sdb1; echo '/dev/sdb1 swap swap defaults 0 0' >> /etc/fstab. It follows the proper sequence to prepare and activate a swap partition on /dev/sdb1. First, `mkswap` initializes the partition as a swap area by writing a swap signature. Then `swapon` activates it immediately. Finally, adding an entry to /etc/fstab ensures the swap is automatically enabled at boot, making it persistent across reboots.

Answer

parted /dev/sdb set 1 swap on

Answer

swapadd /dev/sdb1

Answer

mkfs.ext4 /dev/sdb1; mount /dev/sdb1 /swap

Answer

None of the above

Question 6

A system fails to boot because of a corrupted fstab file. The administrator boots into rescue mode from a RHEL installation ISO. Which command should be run first to mount the root filesystem read-write?

Accepted Answer

mount /dev/mapper/rhel-root /mnt/sysimage. In rescue mode, the root filesystem is not mounted by default. The first step is to mount the logical volume containing the root filesystem (e.g., /dev/mapper/rhel-root) to a temporary mount point like /mnt/sysimage so that you can access and repair the corrupted /etc/fstab file. Option A correctly uses the mount command with the device and mount point, which is the standard procedure for RHEL rescue environments.

Answer

mount -o rw,remount /sysroot

Answer

chroot /mnt/sysimage

Answer

systemctl rescue

Question 7

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?

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 8

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 9

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 10

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 11

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 12

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 13

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 14

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 15

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