Virtualbox

Compress Virtualbox image

Reclaim space

Look for big directories

du -hs .[^.]*

mysql

mysql -ppass -u root
SHOW BINARY LOGS;
PURGE BINARY LOGS TO 'mysql-bin.000293';

docker

sudo systemctl stop docker
sudo rm -rf /var/lib/docker
sudo systemctl start docker

mongo

mongo --quiet --eval 'db.getMongo().getDBNames().forEach(function(i){db.getSiblingDB(i).dropDatabase()})'

Journal

sudo journalctl --vacuum-time=2d

pacman

sudo pacman -Sc
sudo rm /var/cache/pacman/pkg/*

Linux

dd if=/dev/zero of=test.file
rm test.file
sudo shutdown now

Windows

VBoxManage modifyhd --compact "C:\Users\Shook\VirtualBox VMs\Arch\Arch 2-disk1.vdi"

VM options

Use all available logical CPUs (not just physical ones)