LCA Process Management & System Services 2

Question 1

What is the primary purpose of the /proc virtual filesystem in Linux?

Accepted Answer

To provide a kernel interface exposing process and system information

Answer

To store temporary files created by running processes

Answer

To cache compiled process data for faster execution

Answer

To store core dumps generated by crashed processes

Question 2

Which systemctl command lists all units that are currently loaded in memory, including active and failed units?

Accepted Answer

systemctl list-units

Answer

systemctl list-all

Answer

systemctl show-units

Answer

systemctl running

Question 3

What happens when a process receives SIGTERM (signal 15)?

Accepted Answer

It receives a graceful termination request and can perform cleanup before exiting

Answer

It is immediately killed by the kernel with no cleanup

Answer

It pauses execution and waits to be resumed with SIGCONT

Answer

It automatically restarts via its init or systemd configuration

Question 4

Which journalctl command filters log output to show only entries from the systemd unit named 'nginx'?

Accepted Answer

journalctl -u nginx

Answer

journalctl -s nginx

Answer

journalctl --service nginx

Answer

journalctl /nginx

Question 5

Which command changes the scheduling priority of an already-running process with PID 1234 to a nice value of 5?

Accepted Answer

renice -n 5 -p 1234

Answer

nice -n 5 1234

Answer

chnice 5 1234

Answer

nice --pid 1234 5

Question 6

In the crontab entry '30 2 * * 1-5 /usr/local/bin/backup.sh', on which days will the script execute?

Accepted Answer

Weekdays only (Monday through Friday)

Answer

Weekends only (Saturday and Sunday)

Answer

All seven days of the week

Answer

The first five days of each calendar month

Question 7

What is a zombie process in Linux?

Accepted Answer

A process that has exited but remains in the process table because its parent has not read its exit status

Answer

A process consuming 100% CPU indefinitely

Answer

A process running as root without proper authorization

Answer

A process that ignores all termination signals including SIGKILL