nohup on Linux: Run Commands in the Background After SSH Logout

October 18, 2026 · dinesh

nohup on Linux is searched constantly — you start a backup or data import over SSH, close the laptop, and wonder if the process died. nohup (no hang up) tells the shell to ignore the hangup signal so the child keeps running when your session ends.

Alternatives: tmux,
cron,
systemd services.

What nohup Does

When SSH disconnects, the kernel sends SIGHUP to your shell — by default that kills background jobs unless they are immune.

Basic nohup Syntax

Append & to run in the background; capture the PID for later checks.

bashlong job

nohup ./long-backup.sh >> /var/log/backup.log 2>&1 &
echo $! > /var/run/backup.pid

Redirect stdout and stderr

Default nohup.out in the current directory is messy — always point logs somewhere explicit.

bashredirect

nohup myjob.sh > /var/log/myjob.log 2>&1 &

2>&1″ /><figcaption>log file</figcaption></figure>
<h2>disown for Existing Jobs</h2>
<p>Already started a job? <code>disown -h</code> removes it from the shell job table so SIGHUP does not reach it.</p>
<div class=

SSH and Interactive Sessions

nohup is fine for one-off tasks; for repeatable admin work prefer a persistent multiplexer.

TipProduction long runners should be a systemd unit with Restart= and journal logging — not a forgotten nohup.

nohup vs cron vs systemd

Match the tool to how often the job runs and how you need to observe failures.

Verify the Process

Confirm PID still exists and logs are growing before you log out.

bashcheck

ps -p $(cat /var/run/backup.pid) -o pid,cmd
 tail -f /var/log/backup.log

Quick Reference

nohup COMMAND >> log 2>&1 & survives SSH disconnect
Save PID with echo $! for monitoring
Services: use systemd, not eternal nohup

What nohup Does

Basic nohup Syntax

Redirect stdout and stderr

SSH and Interactive Sessions

nohup vs cron vs systemd

Verify the Process

Quick Reference

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