howto create a RAID array with LUKS encryption, madm RAID tools and LVM2

tested on debian squeeze

replace sdX and sdY with the hdd devices of your choice - choose careful!

run badblocks check or dd to overwrite all data with random bit patterns

badblocks -c 10240 -s -w -t random -v /dev/sdX
badblocks -c 10240 -s -w -t random -v /dev/sdY  

or slower and more secure:

dd if=/dev/urandom of=/dev/sdX
dd if=/dev/urandom of=/dev/sdY

wait some hours or days..

: some howtos suggest to run this step over the partitions, not the whole device.. unknown..

Create partitions on two devices

• mark them with the type code FD
• all partitions should be of the same size!

fdisk /dev/sdX 
..
fdisk /dev/sdY

Create the RAID array:

mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdX1 /dev/sdY1

This creates a RAID 1. Choose a free device number for X in /dev/mdX

The device will be created and synchronization of the blocks starts. Check the sync progress and details of the array:

cat /proc/mdstat
mdadm --detail /dev/md1

Encrypting the Block Devices

cryptsetup -c aes-cbc-essiv:sha256 -y -s 256 luksFormat /dev/mdX

Unlocking the Block Devices

cryptsetup luksOpen /dev/mdX

Create Logical Volume with Logical Volume Manager (LVM)

..if you like. https://en.wikipedia.org/wiki/Logical_Volume_Manager_%28Linux%29#Common_uses