On Wed, Apr 10, 2019 at 6:36 PM Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > On 11/4/19 6:44 am, Mark Wagner wrote: > > I've got a server with a five-disk RAID-6 array. Last night, power to > > the server went out, and when I powered it back up, one of the disks > > failed. During bootup, the RAID array was assembled as an inactive > > four-disk RAID-0 array with four spares rather than the expected > > degraded RAID-6, and manually assembling the array doesn't give a > > different result. Any idea how I can get my array back? There > > doesn't appear to be anything wrong with the four remaining disks, it > > simply isn't working. > > > > Steps I used to manually assemble the array: > > > > # mdadm --stop /dev/md2 > > > > # mdadm --assemble --verbose /dev/md2 /dev/sd[abcd] > > mdadm: looking for devices for /dev/md2 > > mdadm: /dev/sda is identified as a member of /dev/md2, slot 1. > > mdadm: /dev/sdb is identified as a member of /dev/md2, slot 0. > > mdadm: /dev/sdc is identified as a member of /dev/md2, slot 3. > > mdadm: /dev/sdd is identified as a member of /dev/md2, slot 4. > > mdadm: added /dev/sda to /dev/md2 as 1 > > mdadm: no uptodate device for slot 2 of /dev/md2 > > mdadm: added /dev/sdc to /dev/md2 as 3 > > mdadm: added /dev/sdd to /dev/md2 as 4 > > mdadm: added /dev/sdb to /dev/md2 as 0 > > mdadm: /dev/md2 assembled from 4 drives - need all 5 to start it (use > > --run to insist). > > Did you do what the log told you to do? > > mdadm --stop /dev/md2 > > mdadm --assemble --verbose --run /dev/md2 /dev/sd[abcd] > > mdadm --assemble --help says this: > --run -R : Try to start the array even if not enough devices > for a full array are present It's currently showing as an inactive RAID-0 array. I'm worried that using "--run" will assemble them as an *active* RAID-0 array, with the corresponding loss of data. I've got backups, but I really don't want to need to use them. -- Mark
