RHCSA RHCSA Linux System Administration 3

Question 1

Which command schedules a one-time job to run at 2:30 PM today using the 'at' utility?

Accepted Answer

at 14:30

Answer

The 'at' command accepts 24-hour time directly; after entering the command, you type your job and press Ctrl+D.

Question 2

What does the 'ss -tulnp' command display?

Accepted Answer

TCP and UDP listening sockets with process info and no DNS resolution

Answer

-t=TCP, -u=UDP, -l=listening, -n=no DNS, -p=process; combined they show listening network sockets with PIDs.

Question 3

A filesystem mounted at /data is running low on space. The underlying LV is in vg0. Which command extends it by 10GB?

Accepted Answer

lvextend -L +10G /dev/vg0/data && xfs_growfs /data

Answer

lvextend grows the LV and xfs_growfs expands the XFS filesystem online to fill the new space.

Question 4

Which file should be edited to set a system-wide default umask for all users?

Accepted Answer

/etc/profile

Answer

/etc/profile is sourced for all login shells and is the standard place to set a system-wide umask.

Question 5

How do you set the hostname to 'webserver01.example.com' persistently using a single command?

Accepted Answer

hostnamectl set-hostname webserver01.example.com

Answer

hostnamectl set-hostname updates /etc/hostname and applies the change immediately and persistently.

RHCSA Exam Practice Test