EX200 Practice Test 30 — 15 Questions

Question 1

A cron job runs a script every hour and leaves many log files. The administrator wants to clean up log files older than 7 days in /var/log/myapp/. Which command should be added to a weekly cron job?

Accepted Answer

find /var/log/myapp -type f -mtime +7 -delete. `-mtime +7` matches files whose modification time is older than 7 days, and `-delete` safely removes them. This is the most efficient and standard approach for cleaning up old log files in a cron job, as it avoids spawning a separate process for each file.

Answer

find /var/log/myapp -type f -atime +7 -delete

Answer

find /var/log/myapp -type f -mtime +7 -exec rm {} \;

Answer

find /var/log/myapp -type f -ctime +7 -delete

Question 2

A user reports that a script in their home directory fails to execute. The script has permissions -rw-r--r-- and is owned by the user. Which command will allow execution for the owner?

Accepted Answer

chmod u+x script.sh. The script currently has permissions `-rw-r--r--`, meaning the owner has read and write but not execute. To allow the owner to execute it, you need to add the execute permission for the owner only. `chmod u+x script.sh` adds the execute bit for the user (owner) without affecting group or others, which is the precise requirement.

Answer

chmod u+r script.sh

Answer

chmod a+x script.sh

Answer

chmod u-x script.sh

Question 3

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 4

An administrator needs to list the permissions, owner, group, and filenames of all files in /var/log, including hidden files, in a human-readable format. Which command does this?

Accepted Answer

ls -lah /var/log. `ls -lah /var/log` combines the `-l` (long format), `-a` (show all files including hidden ones), and `-h` (human-readable sizes) flags. This meets all requirements: listing permissions, owner, group, filenames, and hidden files with sizes in KiB/MiB/GiB.

Answer

ls -lh /var/log

Answer

ls -la /var/log

Answer

ls -ld /var/log

Question 5

An administrator wants to display a list of all currently logged-in users. Which command is most appropriate?

Accepted Answer

who. The `who` command displays a list of currently logged-in users along with their terminal, login time, and originating host. It is the most straightforward and appropriate command for this specific task, as it directly queries the system's utmp database to show active sessions.

Answer

w

Answer

last

Answer

users

Question 6

After adding a new disk to a volume group, which command is used to extend a logical volume by 2GB?

Accepted Answer

lvextend -L +2G /dev/vg/lv. After adding a new disk to a volume group, the `lvextend -L +2G /dev/vg/lv` command extends the logical volume by exactly 2 GB. The `-L +2G` syntax specifies the additional size to add, and the target is the logical volume path. This is the standard LVM command for increasing logical volume size without specifying a physical extent range.

Answer

vgextend vg /dev/sdb

Answer

resize2fs /dev/vg/lv

Answer

pvcreate /dev/sdb

Question 7

Arrange the steps to configure a logical volume snapshot named 'snap_lv_data' of logical volume 'lv_data'.

Accepted Answer

Create snapshot using lvcreate -s, Mount snapshot to a directory, Perform operations on snapshot, Unmount snapshot, Remove snapshot. The correct sequence for configuring a logical volume snapshot is to first create the snapshot with lvcreate -s, mount it to access its contents, perform necessary operations (such as backups), unmount the snapshot, and finally remove it to clean up. Common mistakes include mounting or operating on the snapshot before it exists, or removing it prematurely.

Answer

Mount snapshot to a directory, Create snapshot using lvcreate -s, Perform operations on snapshot, Unmount snapshot, Remove snapshot

Answer

Create snapshot using lvcreate -s, Perform operations on snapshot, Mount snapshot to a directory, Unmount snapshot, Remove snapshot

Answer

Create snapshot using lvcreate -s, Mount snapshot to a directory, Remove snapshot, Perform operations on snapshot, Unmount snapshot

Question 8

Match each systemd unit type to its purpose.

Accepted Answer

service: Manages daemon processes. Systemd unit types define system resources: service (daemons), socket (IPC), target (group/synchronization), timer (scheduled activation). Common confusions involve mixing mount with service and target with timer.

Answer

service: Manages file system mount points

Answer

timer: Groups units to define synchronization points

Question 9

A container running a database service needs to persist data across restarts. The administrator decides to use a named volume. Which command creates a named volume and mounts it correctly?

Accepted Answer

podman volume create dbdata && podman run -v dbdata:/var/lib/mysql mydb. It first creates a named volume with `podman volume create dbdata`, then mounts that named volume to the container's `/var/lib/mysql` directory using the `-v` flag. Named volumes are managed by Podman and persist data independently of the container lifecycle, ensuring data survives container restarts or removal.

Answer

podman run -v /var/lib/mysql:/var/lib/mysql mydb

Answer

podman run --mount type=bind,src=dbdata,dst=/var/lib/mysql mydb

Answer

podman run --mount type=tmpfs,dst=/var/lib/mysql mydb

Question 10

A system administrator needs to ensure that the user 'jdoe' cannot log in via SSH but can still use other services like FTP. Which approach should the administrator take?

Accepted Answer

Change the user's shell to /sbin/nologin. Changing the user's shell to /sbin/nologin prevents interactive login via SSH (which requires a valid shell listed in /etc/shells) while still allowing non-interactive services like FTP, which typically do not check the user's shell. This approach specifically blocks SSH access without locking the account or affecting other authentication methods.

Answer

Lock the user account with 'usermod -L jdoe'

Answer

Delete the user's password with 'passwd -d jdoe'

Answer

Remove the user's home directory

Question 11

Which three actions enhance security for user accounts on a Red Hat Enterprise Linux system? (Choose three.)

Accepted Answer

Enforcing password complexity via pam_pwquality.. Option A is correct because enforcing password complexity via pam_pwquality (configured in /etc/security/pwquality.conf and applied through the pam_pwquality PAM module) requires users to choose strong passwords, reducing the risk of brute-force and dictionary attacks. Option B is correct because setting PermitRootLogin no in /etc/ssh/sshd_config prevents direct root logins over SSH, forcing attackers to compromise a normal account and then escalate privileges, which adds a layer of defense. Option E is correct because SSH key-based authentication uses asymmetric cryptographic key pairs instead of reusable passwords, making credential guessing, brute-force, and password-reuse attacks ineffective. Option C is not appropriate because granting all users unrestricted sudo access to run all commands violates least privilege and effectively gives every account root-equivalent power. Option D is not appropriate because setting password expiration to 0 days disables expiration, allowing passwords to remain valid indefinitely and increasing the window of exposure if a password is compromised.

Answer

Granting all users sudo access to run all commands.

Answer

Setting the password expiration to 0 days.

Question 12

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 13

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

Accepted Answer

find /etc -name "*.conf". 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 14

A system administrator wants to allow incoming HTTPS traffic on the default zone of firewalld. Which command should be used?

Accepted Answer

firewall-cmd --add-service=https --permanent. The `--add-service=https` option adds the predefined HTTPS service (port 443/tcp) to the firewalld configuration. The `--permanent` flag ensures the rule persists across reboots. By default, the command applies to the default zone if no zone is specified, which matches the requirement to allow HTTPS traffic on the default zone.

Answer

firewall-cmd --add-port=443/tcp --zone=public --permanent

Answer

firewall-cmd --enable-service=https

Answer

firewall-cmd --add-rule=allow https

Question 15

A system administrator writes the script shown. The /etc directory contains .conf files with spaces in their names (e.g., "my config.conf"). What is the most accurate description of the script's behavior?

Accepted Answer

The script will split filenames with spaces into multiple words, causing errors.. The script uses a for loop with `for file in /etc/*.conf`, which relies on shell globbing. When the glob expands, filenames with spaces (e.g., "my config.conf") are treated as separate words due to word splitting, causing the loop to iterate over each word rather than each file. This results in errors when commands like `echo` or `cp` receive broken paths.

Answer

The script will correctly process all .conf files, including those with spaces.

Answer

The script will only process the first .conf file and then exit.

Answer

The script will not execute because of a syntax error.