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Linux Survival Basics

Read-only, can be slow

Read Recent Logrotate Journal

You need recent logrotate service output.

Command

journalctl -u logrotate --since '7 days ago' --no-pager

Before you run this

System impact: Read-only. Can create load on large logs, directories, filesystems, or process tables.

When not to use it: Do not paste full logs publicly without redacting paths.

Expected output

Recent logrotate unit logs, errors, and skipped-file messages.

System impact

Read-only, can be slow. Nothing changes. The command reads current state and prints diagnostic evidence.

Scope this to the smallest useful path or service on busy systems.

Recovery / rollback: no state is changed.

When to use it

Use after debug output or timer status.

When not to use it

Do not paste full logs publicly without redacting paths.

Example run

Commands shown

These are the commands shown for inspection. Treat them as an example, not proof that your system will behave identically.

  1. journalctl -u logrotate --since '7 days ago' --no-pager
  2. journalctl -u logrotate --since '7 days ago' --no-pager

next steps

Related commands

Linux Survival Basics Can be slow

Read Recent systemd Timer Logs

Timer logs show whether systemd attempted to trigger the task.

journalctl -u backup.timer --since "24 hours ago" --no-pager
Linux Survival Basics Can be slow

Find OOM Killer Lines in the Kernel Journal

Before restarting a service, prove whether the kernel killed it.

journalctl -k --since '24 hours ago' --no-pager | grep -iE 'out of memory|oom-killer|killed process'
Linux Survival Basics Can be slow

Spot OOM Kills in the Kernel Journal

Exit code 137 often means the kernel has something to say.

journalctl -k --since "2 hours ago" --no-pager -o short-iso | grep -Ei 'out of memory|oom|killed process'
Linux Survival Basics Can be slow

Read Mount and fstab Warnings

The boot journal often names the mount or dependency that failed.

journalctl -b -p warning --no-pager | grep -iE 'mount|fstab|dependency'

next diagnostic step

Where to go from this command

Study mapping

Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.

  • LPIC-1 style command-line practice
  • LFCS style performance-task practice
  • Linux+ style troubleshooting review

Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.