LFCS Certification Process and Job Scheduling 4

Question 1

What does the `ionice` command control?

Accepted Answer

The I/O scheduling class and priority of a process

Answer

`ionice` sets or gets the I/O scheduling class (idle, best-effort, real-time) and priority for a process.

Question 2

A systemd service file has `Restart=on-failure`. When will systemd NOT restart the service?

Accepted Answer

When the service exits with a zero exit code (success)

Answer

`Restart=on-failure` only restarts the service on non-zero exit codes, signals, or timeouts — not on clean exit (code 0).

Question 3

Which command shows which CPU core each process is currently running on?

Accepted Answer

ps -eo pid,psr,comm

Answer

`ps -eo pid,psr,comm` outputs each process's PID, processor (CPU core), and command name.

Question 4

What is the effect of running `taskset -c 0,2 ./myapp`?

Accepted Answer

Restricts myapp to run only on CPU cores 0 and 2

Answer

`taskset -c 0,2` sets the CPU affinity mask, restricting the process to only run on the specified cores.

Question 5

What happens to background jobs when you close a terminal without using `nohup` or `disown`?

Accepted Answer

They receive SIGHUP and typically terminate

Answer

When a terminal closes, it sends SIGHUP to all processes in its session; most processes terminate upon receiving it.

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