On Saturday May 30, dave@xxxxxxxxxxx wrote: > [First-time poster, done plenty of googling and archive searching > before sending this, so if it's already been covered my apologies in > advance...] > > Hello All- > > I am running a 3-disk RAID-5 using kernel 2.6.24 and mdadm 2.6.3 under > Ubuntu server 8.04LTS. I'm trying to add a spare drive to the array. > > /dev/md0 == /dev/sdc, /dev/sdd, /dev/sda > > I want to add /dev/sdb1 as a spare partition, so I tried `mdadm > /dev/md0 --add /dev/sdb1` ... this worked great; running `mdadm > --detail /dev/md0` shows 3 active and 1 spare. Cool! > > However, after a reboot, I'm back to 3 active and 0 spare drives. I > tried adding the spare to my DEVICES list in /etc/mdadm/mdadm.conf, > and adding a SPARES=1 attribute to the ARRAY line in that file, still > no persistence. I tried running `update-initramfs -u` after changing > mdadm.conf (per an IRC suggestion) but still no persistence. This should "just work". There might be some hints in /var/log/messages if you'd like to post that. > > -- Is it possible to do what I'm trying to do? Definitely. > -- Do I need to create the array anew using `mdadm --create` and > specifying "--spare-devices=1 /dev/sdb1" during creation? No. > -- Will creating the array again risk corrupting the data already present? There is always a risk - you might type the wrong command by mistake. Other than that there is no risk. However doing so won't gain you anything. > -- Is there any way to instantiate a superblock on /dev/sdb1 so that > it can be associated with this array's UUID? You have already done that. Use mdadm --examine /dev/sdb to confirm. > -- I have the ARRAY line (in mdadm.conf) specified by UUID; could this > be causing the spare to be excluded, since it (presumably) does not > have a superblock? No. And it does have a superblock. NeilBrown -- 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
