Finding what to delete on Linux

Clearing Docker Files

docker container prune -f ;
docker image prune -f ;
docker network prune -f ;
docker volume prune -f

Deleting Old System Logs

Let's Encrypt:

rm /var/log/letsencrypt/*

Recursively delete old .gz logs:

find /var/log -type f -name "*.gz" -exec rm -i {} \;

Remove Old System Packages

apt autoremove

Deleting old Kernels

apt -y install byobu
purge-old-kernels

Or Manually:

Check what Kernel you are currently using so you can make sure you don't delete it:

uname -r

List installed Kernels

dpkg --list | grep linux-image

Delete specific kernel versions:

apt purge linux-image-<version>-generic