August 22, 2020
Use partitions instead of raw devices and make sure the partitions are a bit smaller than the actual device. This makes it easier to replace the device with a new one of another manufacturer.
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1
mdadm --detail --scan | tee -a /etc/mdadm/mdadm.conf
To show the status of your raid:
cat /proc/mdstat
cryptsetup -v luksFormat /dev/md0
dd bs=512 count=4 if=/dev/urandom of=/root/keyfile iflag=fullblock
chmod 600 /root/keyfile
cryptsetup luksAddKey /dev/md0 /root/keyfile
cryptsetup open /dev/md0 md0_crypt --key-file /root/keyfile
blkid /dev/md0
/etc/crypttab
md0_crypt UUID=2a5375bf-2162-413c-a6a8-fbeb47659c85 /root/keyfile luks