LFCS Process and Job Scheduling Questions and Answers

Question 1

A system administrator needs to schedule a backup script located at `/usr/local/bin/backup.sh` to run every day at 3:30 AM. Which of the following is the correct crontab entry to accomplish this?

Accepted Answer

`30 3 * * * /usr/local/bin/backup.sh`

Answer

`* * 3 30 * /usr/local/bin/backup.sh`

Answer

`at 3:30am /usr/local/bin/backup.sh`

Answer

`30 3 * * * root /usr/local/bin/backup.sh`

Question 2

You need to run a resource-intensive data processing script, `/opt/scripts/process_data.sh`, tonight at 11:00 PM. The task should only be executed once. Which command is the most appropriate for scheduling this job?

Accepted Answer

`echo "/opt/scripts/process_data.sh" | at 23:00`

Answer

`schedule --time 23:00 /opt/scripts/process_data.sh`

Answer

`0 23 * * * /opt/scripts/process_data.sh`

Answer

`cron -e "0 23 1 * * /opt/scripts/process_data.sh"`

Question 3

A long-running data compilation process with PID 4567 is consuming excessive CPU, negatively impacting other critical services. Which of the following commands would lower its scheduling priority, making it 'nicer' to other processes?

Accepted Answer

`renice 10 4567`

Answer

`nice -n -10 4567`

Answer

`renice -10 4567`

Answer

`kill -15 4567`

Question 4

A system administrator wants to terminate all processes owned by the user `jdoe`. The command should first attempt a graceful shutdown before resorting to more forceful methods. Which command is the most appropriate first step?

Accepted Answer

`pkill -u jdoe`

Answer

`killall -KILL -u jdoe`

Answer

`kill -9 $(ps -u jdoe -o pid=)`

Answer

`pkill -HUP -u jdoe`

Question 5

While monitoring system performance with the `top` command, you notice a process that needs its priority adjusted. What is the correct interactive keystroke to use within `top` to 'renice' a process?

Accepted Answer

`r`

Answer

`k`

Answer

`p`

Answer

`n`

Question 6

Which of the following `ps` commands is specifically formatted to display only the process ID (PID), the command name (COMM), and the niceness value (NI) for all processes on the system?

Accepted Answer

`ps axo pid,comm,ni`

Answer

`ps -ef`

Answer

`ps aux`

Answer

`ps -l`