EX200 Practice Test 19 — 15 Questions

Question 1

Which TWO commands can be used to create a new user account in Red Hat Enterprise Linux 8?

Accepted Answer

adduser. Both `adduser` and `useradd` are commands that create a new user account in Red Hat Enterprise Linux 8. `adduser` is a symbolic link to `useradd` in RHEL 8, so they perform the same function. The `useradd` command creates a new user with default settings from `/etc/default/useradd` and `/etc/login.defs`, while `adduser` behaves identically.

Answer

groupadd

Answer

usermod

Answer

passwd

Question 2

A server has an LVM volume group 'vg_data' with a logical volume 'lv_data' formatted as ext4. The administrator needs to increase the filesystem size by 2 GB without unmounting. Which set of commands should be used?

Accepted Answer

lvextend -L +2G /dev/vg_data/lv_data && resize2fs /dev/vg_data/lv_data. The filesystem is ext4, which supports online resizing. The `lvextend` command first expands the logical volume by 2 GB, and then `resize2fs` grows the ext4 filesystem to fill the newly allocated space—all without unmounting.

Answer

lvresize -L +2G /dev/vg_data/lv_data && xfs_growfs /mountpoint

Answer

lvextend -L +2G /dev/vg_data/lv_data

Answer

umount /dev/vg_data/lv_data && lvextend -L +2G /dev/vg_data/lv_data && mount /dev/vg_data/lv_data /mountpoint

Question 3

A server running RHEL 9 has an LVM logical volume /dev/vg00/lvol0 formatted with XFS, mounted at /data. The administrator needs to increase the file system size from 100GB to 150GB. Which command sequence should be used?

Accepted Answer

lvextend -L +50G /dev/vg00/lvol0; xfs_growfs /data. It first extends the logical volume by the exact amount needed (+50G) using lvextend, then grows the XFS filesystem to match using xfs_growfs. XFS filesystems can be grown online (no unmount required), and xfs_growfs expands the filesystem to fill the available space in the logical volume.

Answer

xfs_info /data; lvextend -L 150G /dev/vg00/lvol0

Answer

umount /data; lvextend -L +50G /dev/vg00/lvol0; mount /data; xfs_growfs /data

Answer

resize2fs /dev/vg00/lvol0

Question 4

An administrator wants newly created files to be readable and writable only by the owner, and readable by group and others. Which umask value should be set?

Accepted Answer

022. The umask value 022 removes write permissions for group and others, while leaving read and execute permissions intact. Since the default base permissions for files are 666 (rw-rw-rw-), applying umask 022 results in 644 (rw-r--r--), which gives the owner read/write access and group/others read-only access — exactly matching the requirement.

Answer

027

Answer

002

Answer

077

Question 5

After adding a new disk /dev/sdc, a system administrator wants to mount it persistently at /mnt/backup. Which entry in /etc/fstab is most reliable?

Accepted Answer

UUID=abc123... /mnt/backup xfs defaults 0 0. Using the UUID (Universally Unique Identifier) ensures the filesystem is mounted persistently regardless of device name changes (e.g., /dev/sdc could become /dev/sdd after a reboot or disk addition). The UUID is generated when the filesystem is created and remains constant, making it the most reliable method for persistent mounts in /etc/fstab.

Answer

LABEL=data /mnt/backup xfs defaults 0 0

Answer

PARTUUID=def456... /mnt/backup xfs defaults 0 0

Answer

/dev/sdc /mnt/backup xfs defaults 0 0

Question 6

An administrator needs to run a container with a bind mount of the host directory /data to /var/lib/data inside the container. The container image is web:latest. Which command correctly achieves this?

Accepted Answer

podman run -v /data:/var/lib/data web:latest. The `-v` flag in Podman creates a bind mount from the host directory `/data` to the container directory `/var/lib/data`. The syntax `-v /host/path:/container/path` is the standard way to specify a bind mount, and this command correctly maps the host directory to the intended container path.

Answer

podman run -V /data:/var/lib/data web:latest

Answer

podman run -v /var/lib/data:/data web:latest

Answer

podman run -v /data::/var/lib/data web:latest

Question 7

Which THREE of the following commands can be used to display information about file systems?

Accepted Answer

df. The `df` command displays information about mounted file systems, including total size, used space, available space, and mount points. It reads the /proc/mounts file to show file system usage statistics, making it a primary tool for file system information.

Answer

fdisk

Answer

du

Question 8

An administrator runs 'getenforce' and sees 'Enforcing'. They then run 'setenforce 0' but SELinux still denies access to a custom application. What is the most likely reason?

Accepted Answer

The issue is due to file permissions or ACLs, not SELinux.. `setenforce 0` switches SELinux to permissive mode, which logs but does not enforce denials. If access is still denied after this command, the issue is not caused by SELinux enforcement but by traditional Linux file permissions (DAC) or ACLs. The administrator should check `ls -l` and `getfacl` to verify the file's ownership and permissions.

Answer

SELinux is in enforcing mode and the policy is misconfigured.

Answer

The application's SELinux context is incorrect and needs relabeling.

Answer

The change requires a reboot to take effect.

Question 9

A system administrator needs to ensure that data written to a container's `/var/lib/mysql` directory persists after the container is removed. Which TWO methods accomplish this requirement?

Accepted Answer

Create a named volume with `podman volume create` and mount it.. A named volume created with `podman volume create` is managed by Podman and persists independently of the container lifecycle. When mounted to `/var/lib/mysql`, data written to that directory is stored in the volume and remains available even after the container is removed. This is the recommended method for persistent data in production environments.

Answer

Use the `--read-only` flag.

Answer

Use the `--tmpfs` flag.

Answer

Use the `--rm` flag when running the container.

Question 10

An administrator wants to view only the error messages from the kernel ring buffer since last boot. Which command should be used?

Accepted Answer

journalctl -k -p err. `journalctl -k -p err` filters the kernel messages (`-k`) from the systemd journal by priority level `err` (error), showing only error-level kernel messages since the last boot. This is the standard way to view kernel error messages in modern RHEL/CentOS systems using systemd-journald.

Answer

cat /var/log/kernel-errors

Answer

dmesg -p err

Answer

systemctl status kernel

Question 11

Refer to the exhibit. What is the primary security concern with this sudo configuration?

Accepted Answer

The less command allows executing shell commands via !, enabling privilege escalation.. The `less` command, when executed with sudo, allows the user to escape to a shell by typing `!command` from within the pager. This bypasses the intended restriction of only running `/usr/bin/less` as root, enabling arbitrary command execution with elevated privileges. The NOPASSWD directive further compounds the risk by removing the password prompt, making the escalation trivial.

Answer

The NOPASSWD option eliminates the need for a password.

Answer

The entry uses (ALL) instead of (root), allowing jane to run as any user.

Answer

The command /usr/bin/less can be used to read any file.

Question 12

A system administrator runs the command 'ls -l' and sees that a file has permissions '-rwxr-xr-x'. The administrator wants to remove execute permission for the group and others while keeping it for the owner. Which chmod command should be used?

Accepted Answer

chmod go-x file. The command 'chmod go-x file' removes execute permission for group (g) and others (o) while leaving the owner's permissions unchanged. The current permissions '-rwxr-xr-x' indicate owner has rwx, group has r-x, and others have r-x, so removing execute from group and others yields '-rwxr--r--'.

Answer

chmod u-x file

Answer

chmod 755 file

Answer

chmod a+x file

Question 13

A script has a syntax error. Which command will help identify the line number of the error without executing the script?

Accepted Answer

bash -n script.sh. The `bash -n` (noexec) option performs syntax checking on a script without executing any commands. If a syntax error exists, Bash reports the error along with the line number, making it the correct tool for identifying syntax errors in a script without running it.

Answer

which bash

Answer

set -x

Answer

bash -v script.sh

Question 14

A system administrator needs to ensure that the user 'jdoe' can read files in the shared directory /project/data which is owned by group 'project'. The user 'jdoe' is currently not a member of the 'project' group. Which TWO steps should the administrator take to add 'jdoe' to the 'project' group? (Choose two.)

Accepted Answer

gpasswd -a jdoe project. `gpasswd -a jdoe project` adds the user 'jdoe' to the 'project' group by appending the user to the group's member list in /etc/group. This command is specifically designed for group membership management and does not require the user to be logged out; the change takes effect on the next login.

Answer

groupmod -A jdoe project

Answer

vigr to add jdoe to project group

Answer

useradd -G project jdoe

Question 15

An IT department runs a web server that stores user uploads on an ext4 filesystem on /dev/sdb1 mounted at /uploads. Recently, the partition has run out of space. The administrator checks with df -h and sees 100% usage. However, du -sh /uploads shows only 2GB used. The administrator suspects deleted files still held open by processes. Which command should be used to identify and resolve the issue?

Accepted Answer

lsof +L1 /uploads to find deleted open files, then kill processes. The discrepancy between `df -h` showing 100% usage and `du -sh /uploads` showing only 2GB indicates that deleted files are still held open by running processes. The `lsof +L1 /uploads` command lists files with a link count of zero (deleted but still open), and killing the associated processes releases the disk space. This is a classic scenario on ext4 filesystems where file descriptors prevent space reclamation until the process closes the file.

Answer

rm -rf /uploads/* to clean all files

Answer

fsck /dev/sdb1 to repair filesystem

Answer

resize2fs /dev/sdb1 to shrink filesystem