linux

a collection of notes for sysadmin and general linux tasks that i find myself having to look up over and over again.

ubuntu

dist upgrade

sudo apt update
sudo apt upgrade
sudo apt dist-upgrade
sudo apt autoremove
sudo do-release-upgrade
sudo reboot now

sometimes after that there are some random dpkg / apt errors:

sudo dpkg --configure -a
sudo apt --fix-broken install

add desktop launcher

• example file in /usr/share/applications/wally.desktop

[Desktop Entry]
Type=Application
Name=Wally
Comment=USB Flasher for Ergodox EZ
Version=3.0.23
Exec=/usr/local/bin/wally
Icon=/opt/wally/appicon.png
Terminal=False
Categories=Firmware

clean up

sudo apt-get clean
sudo apt-get autoremove --purge

arch linux

These are some notes for myself when setting up arch.

pacman

setup

before you can use the package manager pacman you need to run:

pacman-key --init

This sets up your ability to set some keys and then use them to check the fingerprints on packages you’re going to install.

If you’re on a raspberry pi, you’ll need to add the keys for archlinuxarm in particular:

pacman-key --populate archlinuxarm

Thereafter you can go about installing whatever you need.

If you need to remove all the keys you have added to start over, you can:

rm -rf /etc/pacman.d/gnupg

before running the init again.

base packages

In order to get make, and a bunch of basic tooling:

pacman -S base-devel

AUR client

I always need to download some AUR packages. Usually we still need to download a client:

git clone https://aur.archlinux.org/yay.git
cd yay
makepkg -si

PopOS

Sometimes my system76 laptop’s audio just stops working. This seems to fix it:

systemctl --user restart pulseaudio
rm -r ~/.config/pulse
pulseaudio -k

inserting emojis

I can never remember this:

• Ctrl + Shift + E + Space: then search via word tags

disk space

df -h
du -h -d 1 . --exclude proc

journal logs

journalctl --rotate
journalctl --vacuum-size=100M
journalctl --vacuum-time=10d

docker

docker system prune -a
docker volume prune -a

snap

snap set system refresh.retain=2

memory

sometimes you run out of memory on tiny machines. don’t forget to use swap!

sudo fallocate -l 1G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile

sudo swapon /swapfile
sudo swapon --show

sudo cp /etc/fstab /etc/fstab.bak
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

cat /proc/sys/vm/swappiness
sudo sysctl vm.swappiness=10

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