yum install cryptsetup
Switch off swap
comment out existing swap partition is /etc/fstab
Wipe swap partition
dd if=/dev/zero of=/dev/mapper/VolGroup00-swap
add the swap partition to /etc/crypttab
If it is not already created, create the /etc/crypttab file. Add an entry to /etc/crypttab file. .
swap /dev/mapper/VolGroup00-swap /dev/urandom swap
Add the following entry to /etc/fstab file.
/dev/mapper/swap none swap defaults 0 0
The next time you boot the system and the /etc/rs.sysinit script executes, it creates a raw dm-crypt device with a random key and formats it as a swap device. During /etc/fstab processing, the swap device is activated.
Reboot the system.
Verify that the swap space is encrypted.
You should see a new entry for the added swap file system. You can see it listed below in the second entry, in our example.
Filename Type Size Used Priority
/dev/dm-2 partition 2064376 580 -1
Voila. your swap partition has been encrypted