Free Red Hat EX200 RHCSA Practice Questions

Question 1

NetworkManager saves every profile created or changed with nmcli to disk, so no configuration file has to be edited by hand. Setting ipv4.method to manual makes NetworkManager use the address in ipv4.addresses instead of DHCP, and leaving ipv4.gateway empty keeps a second default route off the storage network. The disabled value for ipv6.method turns IPv6 off for this profile only. A modify command changes only the stored profile, so nmcli connection up applies it now, and connection.autoconnect, which is yes for a new profile, activates it again at every boot.

Question 2

useradd -G only accepts groups that already exist, so admin is created first; if it is already there, groupadd just reports that and nothing changes. The -G option then sets admin as a supplementary group for harry and natasha, and -s /sbin/nologin gives tom a shell that refuses interactive logins. Linux user names are case-sensitive, so the check must be id natasha. The last field of tom's /etc/passwd line shows his login shell.

Question 3

SIMULATION

Create a directory named admins under /home. Its group must be the admin group. Group members must be able to read and write, while other users must not be able to access it. Files created in it by users of the same group must also belong to the admin group.

Completed Answer

Create a directory with specific permissions so the admin group can read and write, others cannot access it, and files inherit the admin group ownership.

Line 1 → cd /home/

Line 2 → mkdir admins

Line 3 → chown :admin admins/

Line 4 → chmod 770 admins/

Line 5 → chmod g+s admins/

How To Work It Out

1. Navigate to /home/ where the directory will be created.

2. Create the admins directory that will serve as the shared directory.

3. Change its group to admin with chown :admin, leaving the owner unchanged.

4. Set permissions to 770 so owner and group have full access (7) while others have no access (0).

5. Apply the setgid bit (g+s) so files created within inherit the directory's admin group instead of the creator's group.

The configuration establishes a shared directory owned by the admin group with read-write permissions only for the owner and group members (770). The setgid bit (g+s) is critical because it forces any files created within the directory to automatically inherit the admin group as their group owner, rather than defaulting to the creator's primary group. This ensures consistent group ownership for all content in the directory while preventing access from other users.

Question 4

SIMULATION

Configure a scheduled task to run the echo hello command at 14:23 every day.

Completed Answer

Configure a cron job to execute the echo hello command every day at 14:23 (2:23 PM).

Line 1 → which echo

Line 2 → crontab -e

Line 3 → 23 14 * * * /bin/echo hello

Line 4: Verify → crontab -l

How To Work It Out

1. First, verify the location of the echo command using which to ensure the correct path.

2. Open the crontab editor with crontab -e to create or modify the scheduled task.

3. Enter the cron expression with minute 23, hour 14 (24-hour format), and asterisks for day, month, and day-of-week to run daily at 14:23.

4. After saving, verify the cron job was created successfully by listing the crontab entries with crontab -l.

Cron uses a five-field format: minute hour day month day-of-week. To run a command at 14:23 every day, set the minute field to 23 and the hour field to 14 (in 24-hour format), with asterisks in the remaining fields to match every day of every month. A full path is used for the command; on RHEL 10 /bin is a link to /usr/bin, so /bin/echo is the same file that which reports as /usr/bin/echo. The crontab -e command opens the editor, and crontab -l verifies the job was saved correctly.

Question 5

SIMULATION

Find all files owned by harry and copy them to the directory /opt/dir.

Completed Answer

Find all files owned by the user harry and copy them to the /opt/dir directory.

Line 1 → cd /opt/

Line 2 → mkdir dir

Line 3 → find / -user harry -exec cp -rfp {} /opt/dir/ \;

How To Work It Out

1. Change to the /opt/ directory to establish the working location where the target directory will be created.

2. Create the destination directory called 'dir' inside /opt/ to prepare the location for copied files.

3. Use find command with -user harry to search the entire filesystem for files owned by harry, then use -exec with cp -rfp to recursively copy those files with preserved permissions to /opt/dir/.

The solution requires three sequential steps. First, navigate to /opt/ where the destination will be created. Second, create the 'dir' subdirectory to serve as the target location. Third, use find / -user harry to search all directories starting from root for files owned by the user harry. The -exec cp -rfp {} /opt/dir/ \; clause executes a copy command for each found file, where -r copies recursively, -f forces overwrite, and -p preserves file attributes. The {} placeholder represents each found file and the backslash-escaped semicolon terminates the -exec action.

Question 6

SIMULATION

Find all lines containing the string abcde in the file /etc/testfile and write them to the file /tmp/testfile. The lines must appear in the same order as in /etc/testfile.

Completed Answer

Write a command to find all lines containing 'abcde' from /etc/testfile and write them to /tmp/testfile while preserving the original sequence.

Command to execute → grep 'abcde' /etc/testfile > /tmp/testfile

How To Work It Out

1. The task requires searching for lines containing the pattern 'abcde' in the source file /etc/testfile.

2. grep is the appropriate tool for pattern matching and line filtering.

3. The output must be written to /tmp/testfile, which requires output redirection using > (overwrite mode).

4. The > operator writes all matching lines to the destination file in the order they appear in the source, preserving sequence.

The grep command searches for lines matching 'abcde' in /etc/testfile. The > redirection operator sends these matching lines to /tmp/testfile, creating or overwriting the file. grep reads the file from top to bottom and prints each matching line as soon as it finds it, so the lines reach /tmp/testfile in exactly the order they have in /etc/testfile, with nothing added or reordered.

Question 7

fdisk creates the 2G partition, and type 82 marks it as Linux swap on this MBR disk. partx -a adds the new partition to the kernel's view without a reboot, and mkswap writes the swap signature. The fstab line names the partition by UUID, with none in the mount point field, so it is activated at every boot even if device names change. swapon -a enables every fstab swap entry that is not already active, so the original swap partition is left untouched.

Question 8

SIMULATION

Create a user named alex with the user ID 1234 and the password alex111.

Completed Answer

Create a user named alex with user ID 1234 and set the password to alex111.

Command 1 → useradd -u 1234 alex

Command 2 → passwd alex

First password prompt response → alex111

Second password prompt response → alex111

How To Work It Out

1. Use useradd with the -u flag to specify the user ID 1234 and create the user named alex.

2. Execute passwd alex to enter the password change mode for the newly created user.

3. When prompted for the new password, type alex111.

4. When prompted to confirm the password, retype alex111 to verify it matches.

To create a user with a specific user ID in Linux, the useradd command with the -u option is required. The useradd -u 1234 alex command creates the user alex with UID 1234. The passwd command then allows setting the password interactively by prompting twice to confirm the password matches. Both prompts must receive alex111 for the password to be successfully set.

Question 9

5. Run the script and echo $? to see the message and the exit status, which is 0 while sshd is running.

The if keyword runs a command and branches on its exit status: zero selects the then list, anything else selects the else list. systemctl is-active returns 0 when the unit is active and non-zero otherwise, and --quiet suppresses the printed state so only the script's own messages appear. When sshd is running, the last command executed is the echo in the then branch, so the script ends with status 0; the else branch sets status 1 explicitly with exit 1. chmod +x lets root execute the file directly by path.

Question 10

The command substitution $(cat /root/newusers.txt) expands to the file's contents, and word splitting turns each name into one item of the for list, so the body runs once per user. getent passwd queries the account database and exits 0 when the name is found or 2 when it is not, which makes it a clean if condition; its output is discarded to /dev/null. The && after useradd prints the created message only if the account was really added. Running the loop again is safe because existing accounts are skipped.