Got an answer: RTFM! :-) -z, --size= [...] This value can be set with --grow for RAID level 1/4/5/6. If the array was created with a size smaller than the currently active drives, the extra space can be accessed using --grow. The size can be given as max which means to choose the largest size that fits on all current drives.
Tyler MacDonald <ty...@yi.org> wrote: > Hello debian! > > I have a RAID-5 mdadm array with 4x500GB drives (1.4TB usable). I'm > running out of space and am going to buy a new drive, but I would like to > move to 1TB drives (either RAID-5 or RAID-10, haven't quite decided yet). I > can't afford to buy all new 1TB drives at once so I'm thinking about just > adding a fifth drive to the array now, and then upgrading the remaining > drives as I can afford it. > > I've dug around trying to find information on how to do this and haven't > seen anything yet. I've imagined the process to be something like: ("Plan > A") > > 1. One-by-one, replace the 500GB drives with 1TB drives, rebuilding the > array using only the first 500GB of each drive. > > 2. Once all drives are 1TB, do something to tell mdadm to reshape the > array so that the full 1TB from each drive is used > > 3. e2fsck -f /dev/md0 && resize2fs /dev/md0 > > Does step #2 exist? If so, how is it done? > > If that's not possible, I'm considering the following plan: ("Plan B") > > 1. Buy 2x1TB drives, set them up as RAID-5 (1TB usable) > > 2. Copy 1TB of the 1.4TB to the new array > > 3. Degrade my existing 4x500GB array, freeing up 1x500GB drive > > 4. Copy the remaining 400GB to the "spare" drive > > 5. Tear down the 3x500GB array > > 6. Set up 2x500GB from the old array as a 1TB RAID-0 stripe > > 7. Add the 2x500GB RAID-0 to the new RAID-5 as a "1TB drive", > making the new array have 2TB capacity, eg; > mdadm --add /dev/md0 /dev/md1 > mdadm --grow /dev/md0 ... > > 8. Copy the data from the "spare" drive over to the new array > > 9. Repeat step #7 with the remaining 2x500GB drives, resulting in > 3TB capacity on the array > > I'd really prefer to go with "Plan A". It's cheaper to get started with, > far less complicated, and doesn't risk data loss during the move. > > Any ideas? Is this possible? > > Thanks, > Tyler > -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org