documentation/docs/void-desktop-setup/Using-swap.md

Swap can be utilised by the system to free up space in RAM. For most use cases it is recommend to create a swapfile that is one and a half times the size of your RAM.

To create a swapfile of 8 GB use:

# dd if=/dev/zero of=/swapfile bs=8M count=1024 status=progress

To create a different size of swapfile, change the count= amount to a desirable size.

Then to actually add the swap space to your system issue these commands:

# chmod 600 /swapfile
# mkswap /swapfile
# swapon /swapfile

To mount the swap to the system at boot, add the swapfile to your /etc/fstab:

/swapfile none swap defaults 0 0

And do not forget to reconfigure the kernel after updating/etc/fstab:

# xbps-reconfigure -f linux<version>