Creating Page File in Linux

When you installed your linux previously without a swap partition and later you decided to add one, here is what you can do.

# dd if=/dev/zero of=/swap1 bs=1024 count 8192 Create 8MB file
# mkswap /swap1 8192 Make file a swap device
# sync; sync
# swapon /swap1 Activate page file


From:
Oreilly's Essential System Administration, 3rd Edition