Swapping on Ubuntu 20.04 Summary (via DigitalOcean)

Thought this was useful to note, but these are just the commands from this article from DigitalOcean about enabling swap without reading everything (basically a tl;dr): https://www.digitalocean.com/community/tutorials/how-to-add-swap-space-on-ubuntu-20-04

Checking swap:

• swapon --show
• free -h

Enabling (temp):

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

Enabling (perm):

• fallocate -l 1G /swapfile
• cp /etc/fstab /etc/fstab.bak
• echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Configuring (in /etc/sysctl.conf):

Set to minimize swap on VPS to reduce host hardware impact (values between 0-100, 0 being reduced swapping, 100 being more swapping, values here are all the way down to minimize swap usage as much as possible):

• vm.swappiness=1
• vm.vfs_cache_pressure=25

Checking configuration for above:

• cat /proc/sys/vm/swappiness
• cat /proc/sys/vm/vfs_cache_pressure
• cat /proc/sys/<sysctl options, ‘/’=’.’>

Disabling:

• swapoff -a