Linux Tips

linux.md

Linux Tips (Debian Based distros)

Some usefull tips i have collected over the years, use at own risk.

• Users & Groups

  • Add user to group
    sudo usermod -a -G cdrom userName
sudo usermod -aG vboxsf $USER

• Change root password
  sudo passwd root

• Analyze Boot Times
  systemd-analyze critical-chain
systemd-analyze blame
systemd-analyze --user blame

• View journal logs

  • Complete log - journalctl --since today
  • Errors only - journalctl -p 2 --since today
  • Warnings Only - journalctl -p 4 --since today

• View SSD/HDD IO performance
  List drives lsblk -f
  Calculate IO for device sudo hdparm -t /dev/sda2
  Calculate w/ no buffers/cache sudo hdparm -t --direct /dev/sda

• Clear bash history
  history -c

• Restart network
  sudo systemctl restart NetworkManager.service
sudo systemctl restart network

• Network traffic
  sudo nethogs -d 2

• Clear font cache
  fc-cache -f -v

• Create iso image
  dd if=/dev/cdrom of=~/cdrom_image.iso

• Create backup image of entire disk
  Change /dev/sda to your device for backup -
  dd if=/dev/sda conv=sync,noerror status=progress | gzip -c > /Data/backupImage12-23.image.gz

• Restore image to a disk gunzip -c /Data/backupImage12-23.image.gz | dd of=/dev/sda

• Simple python webserver, run in folder of website
  python3 -m http.server 8000 /www/website/
access w/ http://localhost:8000

• Remove python managed restrictions
  sudo rm /usr/lib/python3.11/EXTERNALLY-MANAGED

• apt hold package back from upgrades...
  sudo apt-mark hold packageName
  Verify sudo apt-mark showhold
  Remove sudo apt-mark unhold packageName
  

KDE Plasma 5 Tips & Tricks

• General rules for plasma bugs/issues

  • Go back to basic Plasma Breeze Themes to verify if issue is w/ Plasma or theme you installed
  • Remove last installed plasmoid/widget, some cause memory leaks or unexpected issues
  • Wayland is still being developed, many apps do not work well with wayland or unexepected results,
    revert back to X11 session to verify.

• Wayland icons

  • Qt 5, create window rule using .desktop application name
  • Python Create/Locate matching .desktop entry in $HOME/.local/share/applications
    add to main python - app.setDesktopFileName("$HOME/.local/share/applications/appName")

• Restart Plasma 5 Desktop X11
  kbuildsycoca5 && kquitapp5 plasmashell && kstart5 plasmashell && kwin_x11 --replace &

• Clean dolphin search indexes
  balooctl disable && balooctl purge && balooctl enable && balooctl check

• Clean KDE cache

  • Icons and themes rm $HOME/.config/*.kcache
  • Plasmashell rm -r $HOME/.config/plasmashell
  • Remove everthing rm -r $HOME/.cache
  • Logout after cleaning

• Minimize Qt logging
  Add to /etc/environment - QT_LOGGING_RULES=*.debug=false;qt.*.debug=false;qt5.debug=false;*.warning=false;*.critical=false

• KDE debugging settings
  kdebugdialog5

• Screen locker borked
  loginctl unlock-sessions

• To set presentation mode, prevent sleep mode, screen saver
  inhibit_cookie=$(qdbus org.freedesktop.PowerManagement.Inhibit /org/freedesktop/PowerManagement/Inhibit org.freedesktop.PowerManagement.Inhibit.Inhibit 'yt-dlp' 'downloading')

• To unset presentation mode
  qdbus org.freedesktop.PowerManagement.Inhibit /org/freedesktop/PowerManagement/Inhibit org.freedesktop.PowerManagement.Inhibit.UnInhibit $inhibit_cookie

  • Optimizing kubuntu 22
    • https://txhammer68.github.io/docs/kubuntu.html

This awesome, thanks.