(original article)

Re: Converting RAID5 to RAID6 and other shape changing in md/raid

13 March 2010, 14:15 UTC


I'm trying to do a procedure you describe in the examples, converting a 4 disk raid5 to a 6 disk raid6 volume.

I have added the 2 new disks to the raid5 array (sd[ef]4): md0 : active raid5 sdf4[4](S) sde4[5](S) sdd1[1] sdb1[3] sdc1[2] sda1[0] 937705728 blocks level 5, 128k chunk, algorithm 2 [4/4] [uuuu] bitmap: 1/150 pages [4kb], 1024KB chunk

However, when I run the grow command it aborts: # mdadm --grow /dev/md0 --level=6 --raid-devices=6 --backup-file=/root/raid-backup mdadm level of /dev/md0 changed to raid6 mdadm: Need to backup 1536K of critical section.. mdadm: Cannot set device shape for /dev/md0 mdadm: aborting level change

I'm using the following versions of mdadm and Gentoo kernel: mdadm - v3.1.1 - 19th November 2009 2.6.31-hardened-r11