From this text you will learn (quite generally) how to suspend to
encrypted swap partition and how to resume from it. This is mainly
intended for laptop users who love security although the more encrypted
partitions you have the better...



SUSPEND

Prerequisities: linux 2.6+, cryptsetup, swapoff, mkswap, swapon

Howto:

1. turn off the swap partition
2. setup encryption on swap partition
3. make new swap file system on it
4. turn on the encrypted swap
5. susped to it

swapoff PARTITION
cryptsetup create NAME PARTITION -c CIPHER
mkswap /dev/mapper/NAME
swapon -p 1 /dev/mapper/NAME
echo -n disk > /sys/power/state

Do not forget to add "resume=/dev/mapper/NAME" to kernel command line.



RESUME

Prequisities: linux 2.6+, cryptsetup, shell, mount, scripting abilities

Howto:

1. setup encryption on the swa partition
2. get the minor and major device nod numbers
3. mount sysfs
4. resume from the encrypted swap partition

cryptsetup create NAME PARTITION -c CIPHER
ls -la /dev/mapper/NAME

Now store minor/major in some variables. This part is your homework,
because it is too easy and I am too lazy.

mount -n -t sysfs none /sys
echo -n MINOR:MAJOR > /sys/power/resume

Do not forget to add "resume=/dev/mapper/NAME noresume" to kernel
command line.