Create BTRFS on LUKS on ISW RAID5

btrfs_luks_isw_raid5.md

Five disks, 6TB each. Adjust as needed.

Reset the disks.

for f in /dev/sd[abcde]; do
  sudo dd if=/dev/zero of=$f bs=512 count=1 conv=notrunc
done

Create the RAID array.

sudo dmraid -f isw -C store0 --type 5 --strip 128k --disk "/dev/sda,/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde"
sudo dmraid -s

The last command lists the RAID sets. Output is something like the following.

*** Group superset isw_bcghhjfffj
--> Active Subset
name   : isw_bcghhjfffj_store0
size   : 12524192768
stride : 256
type   : raid5_la
status : ok
subsets: 0
devs   : 5
spares : 0

Copy the set ID from the output before continuing.

sudo dmraid -ay isw_bcghhjfffj_store0
sudo cryptsetup luksFormat /dev/mapper/isw_bcghhjfffj_store0

Enter a password when requested. Remember this password!

sudo cryptsetup luksOpen /dev/mapper/isw_bcghhjfffj_store0 crypt0

Enter the password when requested to open the partition.

sudo mkfs.btrfs -f /dev/mapper/crypt0

Now mount it.

mkdir -p /data
sudo mount /dev/mapper/crypt0 /data

References

• http://superuser.com/questions/670980/raid-0-partitioning-for-linux-installation#671018
• https://linux.die.net/man/8/dmraid
• https://www.digitalocean.com/community/tutorials/how-to-use-dm-crypt-to-create-an-encrypted-volume-on-an-ubuntu-vps