Admins

Destruction du raid:

root@opium:/etc# mdadm --stop /dev/md0
mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running process, mounted filesystem or active volume group?

Il faut d'abord détruire le lvm, donc.

root@opium:/etc# vgremove vg-old
Do you really want to remove volume group "vg-old" containing 3 logical volumes? [y/n]: y
Do you really want to remove active logical volume host-old? [y/n]: y
  Logical volume "host-old" successfully removed
Do you really want to remove active logical volume scopolamine-old? [y/n]: y
  Logical volume "scopolamine-old" successfully removed
Do you really want to remove active logical volume dronabinol-old? [y/n]: y
  Logical volume "dronabinol-old" successfully removed
  Volume group "vg-old" successfully removed

root@opium:/etc# mdadm --stop /dev/md0
mdadm: stopped /dev/md0

On créé un nouveau raid:

root@opium:/etc# mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2
mdadm: /dev/sda2 appears to be part of a raid array:
    level=raid5 devices=3 ctime=Sat Apr  5 18:04:27 2014
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: /dev/sdb2 appears to be part of a raid array:
    level=raid5 devices=3 ctime=Sat Apr  5 18:04:27 2014
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

On met à jour la config et on rebuild l'initramfs pour le prochain redémarrage :

# /usr/share/mdadm/mkconf > /etc/mdadm/mdadm.conf
# update-initramfs  -u

On créé un vg lvm pour expliciter l'implicite (vieux disques, toussa):

# pvcreate /dev/md0
  Writing physical volume data to disk "/dev/md0" 
  Physical volume "/dev/md0" successfully created

# vgcreate opium-old /dev/md0
  Volume group "opium-old" successfully created