[CentOS] RAID1 migration - /dev/md1 is not there

Tue Apr 1 03:49:47 UTC 2008
Les Mikesell <lesmikesell at gmail.com>

Sam Beam wrote:
> I am trying to convert an existing IDE one-disk system to RAID1 using the 
> general strategy found here:
> http://lists.centos.org/pipermail/centos/2005-March/003813.html
> But I am stuck on one thing - when I went to create the second md device with 
> mdadm, 
> # mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/hdb2 missing
> mdadm: error opening /dev/md1: No such file or directory
> And indeed, ls /dev/md* shows only md0, which worked fine.
> I do have the 'raid1' kernel module loaded.
> What am I missing? Do I need to create the nodes manually now?

Add --auto=yes to the create command to add the device node. Udev based 
systems don't have the nodes created ahead of time.

   Les Mikesell
    lesmikesell at gmail.com