swap on a VPS

This can help you get some more out of a low-end VPS, even when you cannot re-partition the drive.

# creation

Create the swapfile:

$ touch /var/swap.img

Size to your liking:

$ dd if=/dev/zero of=/var/swap.img bs=1024k count=1000

Where count is the number of 1024kb size blocks to write to the file. The above command would give a swapfile of 1 GB. Change count to 2000 for 2 GB, for example.

# initialisation

Initialise swap filesystem:

$ mkswap /var/swap.img

Enable swap space:

$ swapon /var/swap.img

Disable swap space:

$ swapoff /var/swap.img

# make permanent

Add to fstab to enable the swap on boot. Add the following line to /etc/fstab:

/var/swap.img none swap sw 0 0