On Mon, 21 Dec 2009 09:35:28 +0000
Robin Hill [off-list ref] wrote:

On Mon Dec 21, 2009 at 03:41:33AM +0000, Kristleifur Daðason wrote:

quoted

Hi all,

I wish to convert my 3-drive RAID-5 array to a 6-drive RAID-6. I'm on
Linux 2.6.32.2 and have mdadm version 3.1.1 with the 32-bit-array-size
patch from here: http://osdir.com/ml/linux-raid/2009-11/msg00534.html

I have three live drives and three spares added to the array. When I
initialize the command, mdadm does the initial checks and aborts with
a "cannot set device shape" without doing anything to the array.

$ mdadm --grow /dev/md_d1 --level=6 --raid-devices=6
--backup-file=/root/backup.md1_to_r6
mdadm: metadata format 1.10 unknown, ignored.
mdadm: metadata format 1.10 unknown, ignored.
mdadm level of /dev/md_d1 changed to raid6
mdadm: Need to backup 1024K of critical section..
mdadm: Cannot set device shape for /dev/md_d1
mdadm: aborting level change

I don't think you can grow and reshape simultaneously.  I think you'll
need to do this as two operations - either grow to a 5 disk RAID5 then
reshape to a 6 disk RAID6, or reshape to a 4 disk RAID6 then grow.

Why do you think that?  If there is something in the documentation that
suggests that, please point it out and I'll change it.

You should be able to change level, layout, number of devices, chunksize
all at the same time.

NeilBrown
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html