Swap file

To use swap with Linux can improve performance in situations where memory is low. Typically, you will be prompted to create a swap partition when installing Linux. But this feels very old-school because you cannot change the size of your swap without re-setting up your computer. So you want to create a swap file.

To create a 1GB swap file and use it, issue

dd if=/dev/zero of=/tmp/swap bs=1024 count=1000000
mkswap /tmp/swap  # write a signature so the system knows this is swap
swapon /tmp/swap
cat >> /etc/fstab << EOF
/tmp/swap none swap pri=100,defaults 0 0
EOF

To find out if your swap is in use, issue the command

swapon -s