On 12/11/12 09:14, starlight.2012q4@xxxxxxxxxxx wrote: > Would like to have the option to zero the > superblock of an incoming drive and have > it treated as a virgin replacement. > > I tried this (I think) by running > > mdadm --add /dev/md2 /dev/sde > > It worked, but assigned the new drive > as device number [2], which seems > incorrect. I tried failing/removing the > drive followed by a > > mdadm --remove /dev/md2 detached > > and repeated the --add with a zero-superblock > drive but it does the same thing every time. > Only way to get it to reuse drive slot 1 > was to do a > > mdadm --grow --raid-devices=1 --force /dev/md2 > > followed by a > > mdadm --grow --add --raid-devices=2 /dev/md2 /dev/sde > > Is this the expected behavior? I find it > confusing and probably don't understand > it properly. > I think (from what I understand) is that you will do the following: 1) Two HDD in raid1 installed, synced, working 2) Install third HDD 3) mdadm --manage /dev/md2 --add /dev/sde (add it as a spare) 4) mdadm --grow /dev/md2 --raid-devices=3 (add the third disk to the array, and let it sync) 5) madam --manage /dev/md2 --fail /dev/sdd (fail the disk you want to remove) 6) mdadm --manage /dev/md2 --remove /dev/sdd (remove the disk from the array) 7) mdadm --grow /dev/md2 --raid-devices=2 (reconfigure the array to only have two disks) 8) Physically remove sdd and send offsite The above process will ensure that you ALWAYS have at least two copies of your live data (ie, two working, fully synced members of the array). I have seen that there are some new features to make a drive as "want replacement", which will do some magic to copy all the data to a spare device without actually removing the drive until the spare is synced or similar. However, I think this is only in very recent kernel, and you might need to do some work in finding the usage details etc. Hope the above helps. Regards, Adam -- Adam Goryachev Website Managers www.websitemanagers.com.au -- 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
