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Linux Survival Basics

Read-only

Read Load Average Before You React

You need a fast snapshot of system load and how long the machine has been running.

Command

uptime

Before you run this

System impact: Read-only. Low when scoped to the shown target.

When not to use it: Do not assume high load always means CPU saturation; blocked I/O can raise load too.

Expected output

A single line showing current time, uptime, user count, and 1, 5, and 15 minute load averages.

System impact

Read-only. Nothing changes. The command prints uptime, users, and load averages.

Recovery / rollback: no state is changed.

When to use it

Use at the start of performance triage to see whether pressure is rising or falling.

When not to use it

Do not assume high load always means CPU saturation; blocked I/O can raise load too.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ uptime

 12:32:44 up 18 days,  3:11,  2 users,  load average: 3.91, 2.44, 1.08

$ ps -eo pid,ppid,stat,pcpu,pmem,comm,args --sort=-pcpu | head -n 10

  PID  PPID STAT %CPU %MEM COMMAND         COMMAND
 1842     1 R    86.4  4.2  app-worker     /srv/app/worker --jobs
 1907     1 S    12.8  1.1  nginx          nginx: worker process
 2011     1 S     4.5  7.9  postgres       postgres: checkpointer
View commands shown

These are the commands shown in the sanitized transcript.

Commands shown

  1. uptime
  2. ps -eo pid,ppid,stat,pcpu,pmem,comm,args --sort=-pcpu | head -n 10

next steps

Related commands

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Compare Kernel and Distro Versions

The distro version and kernel version answer different questions.

printf 'kernel=%s arch=%s distro=%s\n' "$(uname -r)" "$(uname -m)" "$(lsb_release -ds)"
Linux Survival Basics Sensitive output

Show Recent Server Reboots

Confirm whether the server actually rebooted and when.

last -x reboot | head -5
Linux Survival Basics Can be slow

Count Failures by Test File

Turn noisy test logs into a ranked failure list.

grep -RhoE '[A-Za-z0-9_./-]+\.(test|spec)\.(js|ts|py|rb)' logs/ | sort | uniq -c | sort -nr | head
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.

  • lpic1:103-gnu-unix-commands
  • lfcs:essential-commands
  • risk:read-only

Useful for

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

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