Linux · Processes & Perf interview questions

1. A.resume a job in the background / foreground
2. B.show a live view of processes, CPU and memory
3. C.show memory and swap usage, human-readable
4. D.ask a process to terminate gracefully with SIGTERM

Answer + AI explanation with Pro

1. A.top
2. B.free -h
3. C.vmstat 1
4. D.mpstat -P ALL 1

Answer + AI explanation with Pro

1. A.top — show a live view of processes, CPU and memory
2. B.top — report historical memory usage statistics
3. C.top — print the PID(s) of a named process
4. D.top — list processes with an open network connection on port 443

Answer + AI explanation with Pro

1. A.show memory and swap usage, human-readable
2. B.list all running processes with CPU/memory usage
3. C.print the PID(s) of a named process
4. D.change the priority of a running process

Answer + AI explanation with Pro

1. A.renice -n 5 -p PID
2. B.free -h
3. C.bg / fg
4. D.top

Answer + AI explanation with Pro

1. A.free -h — list background jobs of the current shell
2. B.free -h — resume a job in the background / foreground
3. C.free -h — show memory and swap usage, human-readable
4. D.free -h — report per-CPU utilization every second

Answer + AI explanation with Pro

1. A.force-kill a process with SIGKILL (cannot be caught)
2. B.report historical memory usage statistics
3. C.report per-CPU utilization every second
4. D.resume a job in the background / foreground

Answer + AI explanation with Pro

1. A.bg / fg
2. B.vmstat 1
3. C.kill -9 PID
4. D.sar -r

Answer + AI explanation with Pro

1. A.kill -9 PID — start a command with lower CPU scheduling priority
2. B.kill -9 PID — change the priority of a running process
3. C.kill -9 PID — list all running processes with CPU/memory usage
4. D.kill -9 PID — force-kill a process with SIGKILL (cannot be caught)

Answer + AI explanation with Pro

1. A.ask a process to terminate gracefully with SIGTERM
2. B.change the priority of a running process
3. C.report historical memory usage statistics
4. D.show a live view of processes, CPU and memory

Answer + AI explanation with Pro

1. A.kill -9 PID
2. B.kill -15 PID
3. C.lsof -i :443
4. D.nice -n 10 cmd

Answer + AI explanation with Pro

1. A.kill -15 PID — print the PID(s) of a named process
2. B.kill -15 PID — ask a process to terminate gracefully with SIGTERM
3. C.kill -15 PID — report CPU, memory and I/O statistics every second
4. D.kill -15 PID — show memory and swap usage, human-readable

Answer + AI explanation with Pro

1. A.start a command with lower CPU scheduling priority
2. B.show extended per-disk I/O statistics
3. C.report historical memory usage statistics
4. D.list all running processes with CPU/memory usage

Answer + AI explanation with Pro

1. A.sar -r
2. B.free -h
3. C.iostat -x
4. D.renice -n 5 -p PID

Answer + AI explanation with Pro

1. A.iostat -x — start a command with lower CPU scheduling priority
2. B.iostat -x — show extended per-disk I/O statistics
3. C.iostat -x — print the PID(s) of a named process
4. D.iostat -x — report per-CPU utilization every second

Answer + AI explanation with Pro

1. A.show extended per-disk I/O statistics
2. B.print the PID(s) of a named process
3. C.list background jobs of the current shell
4. D.report CPU, memory and I/O statistics every second

Answer + AI explanation with Pro

1. A.ps aux
2. B.vmstat 1
3. C.kill -15 PID
4. D.iostat -x

Answer + AI explanation with Pro

1. A.vmstat 1 — show memory and swap usage, human-readable
2. B.vmstat 1 — list all running processes with CPU/memory usage
3. C.vmstat 1 — list background jobs of the current shell
4. D.vmstat 1 — report CPU, memory and I/O statistics every second

Answer + AI explanation with Pro

1. A.show extended per-disk I/O statistics
2. B.list processes with an open network connection on port 443
3. C.ask a process to terminate gracefully with SIGTERM
4. D.list background jobs of the current shell

Answer + AI explanation with Pro

1. A.vmstat 1
2. B.sar -r
3. C.renice -n 5 -p PID
4. D.lsof -i :443

Answer + AI explanation with Pro

1. A.lsof -i :443 — report per-CPU utilization every second
2. B.lsof -i :443 — list processes with an open network connection on port 443
3. C.lsof -i :443 — resume a job in the background / foreground
4. D.lsof -i :443 — change the priority of a running process

Answer + AI explanation with Pro

1. A.a finished process whose parent hasn't reaped its exit status
2. B.memory architecture where CPUs access local memory faster than remote
3. C.kernel groups that limit and account for CPU/memory/IO per process set
4. D.the average number of running + uninterruptible processes over 1/5/15 min

Answer + AI explanation with Pro

1. A.nohup
2. B.swappiness
3. C.SIGHUP
4. D.load average

Answer + AI explanation with Pro

1. A.load average — kernel groups that limit and account for CPU/memory/IO per process set
2. B.load average — memory architecture where CPUs access local memory faster than remote
3. C.load average — the average number of running + uninterruptible processes over 1/5/15 min
4. D.load average — a finished process whose parent hasn't reaped its exit status

Answer + AI explanation with Pro

1. A.runs a command immune to hangups so it survives logout
2. B.signal 1, often used to make a daemon reload its config
3. C.a symptom typically caused by I/O wait or D-state (uninterruptible) tasks
4. D.the average number of running + uninterruptible processes over 1/5/15 min

Answer + AI explanation with Pro

1. A.OOM killer
2. B.swappiness
3. C.high load, low CPU
4. D.load average

Answer + AI explanation with Pro

1. A.high load, low CPU — a tunable (0–100) controlling how aggressively the kernel swaps
2. B.high load, low CPU — the kernel mechanism that kills a process when memory is exhausted
3. C.high load, low CPU — signal 1, often used to make a daemon reload its config
4. D.high load, low CPU — a symptom typically caused by I/O wait or D-state (uninterruptible) tasks

Answer + AI explanation with Pro

1. A.signal 1, often used to make a daemon reload its config
2. B.a tunable (0–100) controlling how aggressively the kernel swaps
3. C.runs a command immune to hangups so it survives logout
4. D.the kernel mechanism that kills a process when memory is exhausted

Answer + AI explanation with Pro

1. A.OOM killer
2. B.high load, low CPU
3. C.cgroups
4. D.zombie process

Answer + AI explanation with Pro

1. A.OOM killer — kernel groups that limit and account for CPU/memory/IO per process set
2. B.OOM killer — signal 1, often used to make a daemon reload its config
3. C.OOM killer — the kernel mechanism that kills a process when memory is exhausted
4. D.OOM killer — memory architecture where CPUs access local memory faster than remote

Answer + AI explanation with Pro