On Thu, 2 May 2013 13:56:09 +0200 Ole Tange <tange@xxxxxxxxxx> wrote: > I have a RAID60 that I want to expand. > > The current setup is: 2 axles each having 9 disks + 2 spares. > > The future wanted setup is: 4 axles each having 10 disks + 1 spare. > > So I need to do some --grow to reshape the drives. > > I thought this would be enough: > > mdadm -v --grow /dev/md1 --raid-devices=10 --backup-file=/root/back-md1 > mdadm -v --grow /dev/md2 --raid-devices=10 --backup-file=/root/back-md2 > mdadm -v --grow /dev/md0 --raid-devices=4 --add /dev/md3 /dev/md4 > > The last command works, but the 2 first commands fail with: > > mdadm: Need to backup 7168K of critical section.. > mdadm: /dev/md2: Something wrong - reshape aborted I assume you are getting this error when running a test with small loop-back devices - yes? Very sensible to test first. However to reshape a RAID6 from 9 to 10, you need each device to be at least 7*8*chunksize*2 - possibly a bit more than that. Your script uses a chunksize of 128K, so you need at least 15Meg Your script creates 1Meg devices. Try your test with a much smaller chunk size and a somewhat larger device size. NeilBrown > > How can I --grow a RAID6 to use more devices? > > Info about the system: > > $ mdadm --version > mdadm - v3.2.5 - 18th May 2012 > $ uname -r > 3.5.0-17-generic > > This URL includes a Makefile to reproduce the problem: > http://serverfault.com/questions/503832/linux-mdadm-grow-raid6-something-wrong-reshape-aborted > > > /Ole > -- > 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
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