On Thu, Jun 12, 2014 at 12:10:17PM -0400, Bill Horne wrote: > The machine came with a default Ubuntu 13.04 LTS install, which > includes an LVM on /dev/sda, and a blank /dev/sdb. The plan is to > create a degraded RAID1 array on the "spare" drive, and then copy > the "live" drive data into it and subsequently join the two drives > together in a RAID1 array, with LVM on top of RAID1. > > However, we know what they say about the best laid plans ... > > I've managed to create some sort of array, named "md127", but I > haven't been able to figure out how. I did an "mdadm --create" with > a name of "md1", but I've wound up with "md127". It appears to be > working, albeit in degraded mode, but I want to go slowly and figure > out what happened before I wind up with a non-standard install which > might cause problems later.
That's an easy one. mdadm doesn't guarantee naming by device, so you need to either label your partitions (e2label) or use their UUIDs (ls -al /dev/disk/by-uuid to figure it out) and then put them in /etc/fstab as: LABEL=whatever / ext3 defaults 0 0 or UUID=big-long-string / ext3 defaults 0 0 as appropriate. UUID and label are both guaranteed to survive anything that leaves the disk readable. UUID is cross-filesystem. UUID can also be used in mdadm as device names, and that is recommended. > it: of course, that's not the final state I'm aiming for, but for > now I know that it is working with the "md127" name. I don't know > how I wound up with the "md127" name instead of "md1", but if > there's no danger sign in that name, I'm happy to go to the next > step and make "md127" part of the LVM and proceed to add /dev/sda to > the RAID1 array. You're fine, but you probably want to specify it by UUID for /dev/sda, not "/dev/sda". -dsr- _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
