3. Commands

3.1 Creating a crypted partition

In order to create a crypted partition, a normal partition must be created and then be associated to the crypted device.

Creating not crypted partition

The partition can be a normal partition (e.g. /dev/hda1) or a LVM partition (e.g.: /dev/vg0/lv0)

For normal partition:

cfdisk /dev/hda

For LVM (depracated, see "Using dm-crypt with LVM"):

lvcreate -L 1G -n lvmcrypted vg

Creating the crypted device

For normal partition:

cryptsetup -y create crypted /dev/hda1

For LVM (depracated, see "Using dm-crypt with LVM"):

cryptsetup -y create crypted /dev/mapper/vg-lvmcrypted

Creating filesystem on crypted device

Create the filesystem as normaly:

mkfs.reiserfs /dev/mapper/crypted

Updating /etc/crypttab

To make available the crypted partitions after each boot, the crypttab file must be updated.
For normal partition, add a line like the following:

crypted /dev/hda1

crypted /dev/vg/lvmcrypted

Updating /etc/fstab

To mount the crypted partitions after each boot, the mount point must be created and the fstab file must be updated.

Create the mount point:

mkdir /mnt/crypted

/dev/mapper/crypted /mnt/crypted reiserfs defaults

Here, there isn't any difference between normal partition and LVM partitions, because in both cases the access to the data is done via the crypted device.

Mounting crypted partition

Now it's possible the mount the partition:

mount /mnt/crypted

3.2 Removing a crypted partition

Unmounting crypted partition

In order to remove a crypted partition, it must be first unmounted:

umount /mnt/crypted

Removing the crypted device

Now it's possible to remove the crypted device:

cryptsetup remove crypted

Clean up

Don't forget to udpate the /etc/fstab and /etc/crypttab files, and to remove the unused mountpoint and partition.

3.3 Creating a crypted swap

Since data can be temporary copied to the swap, it's a good idea to crypt also the swap.

Also here, first a normal partition must be created and then associated to the crypted device.

Creating not crypted partition

The partition can be a normal partition (e.g. /dev/hda2) or a LVM partition (e.g.: /dev/vg0/lv1)

For normal partition:

cfdisk /dev/hda

For LVM (depracated, see "Using dm-crypt with LVM"):

lvcreate -L 1G -n lvmswap vg

Creating the crypted device

For normal partition:

cryptsetup -y create cryptedswap /dev/hda2

For LVM (depracated, see "Using dm-crypt with LVM"):

cryptsetup -y create cryptedswap /dev/mapper/vg-lvmswap

Creating filesystem

Create a swap filesystem as normally:

mkswap /dev/mapper/cryptswap

Updating /etc/crypttab

To make available the crypted partitions after each boot, the crypttab file must be updated.
For normal partition, add a line like the following:

cryptswap /dev/hda2 /dev/random swap

cryptedswap /dev/vg/swap /dev/random swap

Using /dev/random as key, will create a new random key at each boot and you won't be prompted for a password each time.

Updating /etc/fstab

To mount the crypted swap after each boot, the fstab file must be updated.
Add a line like the following in /etc/fstab:

/dev/mapper/cryptswap none swap sw,pri=1

Also here, there isn't any difference between normal partition and LVM partitions, because in both cases the access to the data is done via the crypted device.

Activating swap

Activate all the swap partitions, just by calling:

swapon -a