CPU#

Some useful links to explain the concepts of CPU processing

Concepts#

_images/cpu-process-contents.png

Types of Processes#

Output of ps command - Explained#

_images/cpu-ps-aux-meaning.png _images/cpu-process-state-codes.png

Commands#

NoHUP &#

_images/cpu-nohup-disown.png

top#

SAR#

Nice / Renice / IOnice#

KILL#

_images/cpu-difference-between-pkill-killall.png

HTop#

Visual representation of all HTop parameters#

_images/cpu-visual-htop.png

HTop command - Explained#

SysDig#

Configuration#

Troubleshooting & Log Parsing#

  • Find the most number of processes running on the system

1sudo ps -AL --no-headers | awk -F: '{print $3}' | cut -d' ' -f2 | sort | uniq -c | sort -n | tail -10
  • Check for zombie processes with PPID

1sudo ps axo stat,ppid,pid,comm | grep -w defunct
  • View Column Headers in ps output

1sudo ps aux | head -1 && sudo ps aux | grep <process-name> | grep -v grep