1# create swap file
 2dd if=/dev/zero of=./swapfile bs=1GB count=40
 3
 4# add permisions
 5chmod 600 ./swapfile
 6
 7# format the swapfile
 8mkswap ./swapfile
 9
10# enable swap on swapfile
11swapon ./swapfile
12
13# check that it is enabled
14swapon --show