On 2013-04-11, Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > I'm pretty sure this will work: > 1) mdadm --manage /dev/md0 --add /dev/sdc1 # Add spare device > 2) mdadm --grow /dev/md0 --level=1 --raid-devices=3 # Grow the array to > three drive raid1 > 3) mdadm --manage /dev/md0 --fail /dev/sdb1 # After the resync is > finished, fail the old disk2 > 4) mdadm --manage /dev/md0 --remove /dev/sdb1 # Now remove the old disk2 > 5) # Now physically remove disk2. > Repeat steps 1, 3, 4, 5 to replace disk1 with disk4. > > 6) mdadm --grow /dev/md0 --level=1 --raid-devices=2 # Reduce the array > back to a two drive raid1 This seems like a reasonable way to replace a RAID1 device without losing redundancy. Is there any way to accomplish the same sort of thing in a RAID5 or 6? I am imagining something like, if I wanted to replace device 0, I'd create a RAID1 with that device and the new device, wait for that build to complete, then break the mirror and remove the old device 0, so that the new drive becomes the new device 0. I suppose one could create a RAID5 out of RAID1 components where each RAID1 is initially degraded, but that seems inelegant. (I think this option may have been suggested on this list at one point.) --keith -- kkeller@xxxxxxxxxxxxxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
