Linux Tips

Regenerate initramfs kernel sudo update-initramfs -u -k all
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
Check Your Frames Per Second

glxgears -info

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
Set Disk Label sudo e2label /dev/nvme0n1p2 "SYSTEM"
Clear bash history history -c
Restart network
sudo systemctl restart NetworkManager.service
sudo systemctl restart network
Network traffic sudo nethogs -d 2
Get external IP address curl http://icanhazip.com/
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
Remove packages dowloaded installed w/ *.deb
Locate package name
apt list --installed | grep -i chrome
sudo apt remove google-chrome-stable

General rules for plasma bugs/issues
- Go back to basic Plasma Breeze Themes/Appearance 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 && plasmashell --replace && 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
Prevent lockscreen/sleep mode, useful for games/presentations

while /bin/true; do qdbus org.freedesktop.ScreenSaver /ScreenSaver SimulateUserActivity ; sleep 5m; done &
appID=$!
kill -9 $appID

Test SDDM login screen sddm-greeter --test-mode --theme /usr/share/sddm/themes/breeze
Test Lockscreen/ScreenSaver /usr/lib/x86_64-linux-gnu/libexec/kscreenlocker_greet --testing --theme /usr/share/plasma/look-and-feel/org.kde.breeze.desktop
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 24
  - https://txhammer68.github.io/docs/kubuntu.html

txhammer68/linux.md