EX200 Practice Test 11 — 15 Questions

Question 1

You are tasked with creating a script that reads a list of usernames from /tmp/users.txt, one per line, and creates a home directory for each user using `mkdir /home/$username`. The script is:

#!/bin/bash
while read username; do
  mkdir /home/$username
done < /tmp/users.txt

However, the script fails for usernames that contain spaces (e.g., 'john smith'). The error is 'mkdir: cannot create directory '/home/john': File exists' and then a separate directory for 'smith'. What is the best fix?

Accepted Answer

Use `while IFS= read -r username` to preserve the line as is.. Option B is correct because setting IFS= and using -r prevents the read command from splitting on spaces and disables backslash escapes. Option A quoting $username is necessary but not sufficient because read still splits. Option C would also split on spaces. Option D disables globbing but does not fix word splitting.

Answer

Change the loop to `for username in $(cat /tmp/users.txt)`.

Answer

Quote $username in the mkdir command as in `mkdir "/home/$username"`.

Answer

Add `set -f` to disable pathname expansion.

Question 2

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.. Options B and E are correct. Mounting a host directory (B) and using a named volume (E) both persist data outside the container's writable layer. Option A is incorrect because --rm removes the container and its anonymous volumes. Option C is incorrect because --read-only makes the filesystem read-only, preventing writes. Option D is incorrect because --tmpfs creates a temporary in-memory filesystem that is lost when the container stops.

Answer

Use the `--read-only` flag.

Answer

Use the `--tmpfs` flag.

Answer

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

Question 3

An administrator adds a new 100GB disk to a RHEL 9 server. Which command should be used first to verify that the kernel has detected the new disk?

Accepted Answer

lsblk. The `lsblk` command lists all block devices detected by the kernel, including newly added disks, by reading the sysfs filesystem. It is the safest and most direct way to verify kernel detection without requiring root privileges or triggering side effects. Option D is correct because it immediately shows whether the 100GB disk appears in the device list.

Answer

udevadm trigger

Answer

dmesg | grep sd

Answer

fdisk -l

Answer

partprobe

Question 4

A user needs to find all files with the '.conf' extension under /etc. Which command should be used?

Accepted Answer

find /etc -name "*.conf". Option D is correct because the `find` command is designed to search for files and directories based on criteria such as name, type, or size. Using `find /etc -name "*.conf"` recursively searches the entire `/etc` directory tree for files ending in `.conf`, which is the standard and most reliable method for this task.

Answer

grep -r "*.conf" /etc

Answer

locate /etc/*.conf

Answer

ls /etc/*.conf

Question 5

Which TWO LVM commands can be used to reduce the size of a logical volume?

Accepted Answer

lvresize. Both `lvresize` and `lvreduce` can reduce the size of a logical volume. `lvresize` is the general-purpose command for resizing LVs, and when used with the `-L` or `--size` option to specify a smaller size, it shrinks the volume. `lvreduce` is a dedicated command that specifically reduces the size of a logical volume, offering the same functionality as `lvresize --size` but with a more explicit name. Both commands require the filesystem to be shrunk first (if it contains data) using tools like `resize2fs` or `xfs_growfs` (though XFS cannot be shrunk).

Answer

lvchange

Answer

lvdisplay

Answer

lvextend

Question 6

An administrator wants to ensure that when a user presses Ctrl+C during a long-running script, the script cleans up temporary files before exiting. Which approach should the script use?

Accepted Answer

Use 'trap' to catch SIGINT and run cleanup.. The `trap` command in Bash allows a script to catch signals like SIGINT (sent when Ctrl+C is pressed) and execute a custom function or command before exiting. By setting `trap cleanup SIGINT`, the script can remove temporary files or perform other cleanup actions automatically, ensuring a graceful termination.

Answer

Use 'set -o ignoreeof' to ignore Ctrl+C.

Answer

Run the script in the background with '&'.

Answer

Use 'set -e' to exit on any error.

Question 7

Which TWO commands can be used to display the current SELinux mode?

Accepted Answer

getenforce. The `getenforce` command (option C) displays the current SELinux mode as either Enforcing, Permissive, or Disabled. The `sestatus` command (option D) provides a detailed status report including the current mode, the loaded policy, and the mode from the configuration file. Both are standard tools for querying the SELinux operational state.

Answer

setenforce

Answer

ausearch

Answer

semanage

Question 8

A developer needs to search for the string 'ERROR' in all files under /var/log, but wants to exclude files ending with '.gz'. Which command is correct?

Accepted Answer

grep -r --exclude='*.gz' 'ERROR' /var/log. Option A is correct because `grep -r` performs a recursive search through all files under /var/log, and the `--exclude='*.gz'` option tells grep to skip any files matching the glob pattern '*.gz'. This combination ensures that only non-compressed log files are searched for the string 'ERROR', meeting the requirement exactly.

Answer

grep -R --exclude='*.gz' 'ERROR' /var/log

Answer

grep -l 'ERROR' /var/log/*.gz

Answer

grep -v '*.gz' -r 'ERROR' /var/log

Question 9

A technician attempts to mount an XFS filesystem from /dev/sdc1 to /mnt/backup but receives: 'mount: /mnt/backup: mount point does not exist.' The directory /mnt/backup does exist. What is the most likely cause?

Accepted Answer

SELinux context of /mnt/backup prevents mounting.. The error message 'mount: /mnt/backup: mount point does not exist' is misleading because the directory does exist. The most likely cause is that SELinux is blocking the mount due to a missing or incorrect context on the mount point. SELinux requires the mount point directory to have a specific context (e.g., `default_t` or a context matching the filesystem type) for the mount to succeed; if the context is wrong or missing, the kernel may treat the directory as nonexistent for the mount operation.

Answer

The directory /mnt/backup is not empty.

Answer

The device /dev/sdc1 does not exist.

Answer

The filesystem on /dev/sdc1 is not XFS.

Question 10

Which TWO commands can be used to display the current date and time in a format like '2023-10-05 14:30:00'?

Accepted Answer

date '+%Y-%m-%d %H:%M:%S'. Option A is correct because the `date` command with the format string `'+%Y-%m-%d %H:%M:%S'` explicitly outputs the current date and time in the requested 'YYYY-MM-DD HH:MM:SS' format. The `%Y`, `%m`, `%d`, `%H`, `%M`, and `%S` specifiers correspond to the year, month, day, hour, minute, and second respectively, giving precise control over the output.

Answer

cal

Answer

timedatectl

Answer

hwclock

Question 11

An administrator needs to terminate a hung process with PID 3456 that does not respond to 'kill -15 3456'. Which signal should be used next?

Accepted Answer

kill -9 3456. Option A is correct because kill -9 (SIGKILL) is the signal of last resort for a process that does not respond to SIGTERM (kill -15). SIGKILL cannot be caught, blocked, or ignored by the process; it forces immediate termination by the kernel. Since the process is hung and unresponsive to SIGTERM, SIGKILL is the appropriate next step.

Answer

kill -15 3456

Answer

kill -19 3456

Answer

kill -1 3456

Question 12

Which TWO commands can be used to create a new directory that will serve as a mount point?

Accepted Answer

install -d /mnt/newmount. Option A is correct because `install -d /mnt/newmount` creates the directory `/mnt/newmount` if it does not already exist, setting it up as a mount point. Option D is correct because `mkdir /mnt/newmount` is the standard command to create a directory, which can then be used as a mount point for a filesystem.

Answer

touch /mnt/newmount

Answer

ln -s /mnt /mnt/newmount

Answer

ln /mnt /mnt/newmount

Question 13

Which THREE of the following are valid options for mounting an ext4 filesystem with specific mount options in /etc/fstab?

Accepted Answer

noexec. The `noexec` option prevents execution of binaries on the mounted filesystem, which is a common security hardening measure. It is a valid mount option for ext4 and can be specified in /etc/fstab.

Answer

relatime

Answer

suid

Question 14

What is the most likely cause of the mount error?

Accepted Answer

The NFS server IP address is unreachable or the nfs-utils package is not installed.. The mount error is most likely caused by the NFS server being unreachable or the nfs-utils package not being installed. Without the nfs-utils package, the system lacks the necessary NFS client tools (e.g., mount.nfs, rpcbind) to mount NFS shares. If the server IP is unreachable, the mount command will fail with a timeout or 'No route to host' error, which is a common issue when network connectivity or NFS services are not properly configured.

Answer

The entry in /etc/fstab is malformed.

Answer

The filesystem type 'nfs4' is incorrect; should be 'nfs'.

Answer

The mount point /mnt/data does not exist.

Question 15

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.. Option D is correct because 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