i have found the bug that prevented your upgraded array to be run by the kernel. For (RAID1 only) we do not upgrade chunksize properly in the upgrade_sb() function. The function is very conservative, it only fixes up known differences, it doesnt do a broad reconfiguration. This is why this bug slipped in. The kernel was conservative too, so it simply refused to run your (otherwise perfect) array. i've put out a new raidtools relase with this fix included. I've tested the fix by creating an array identical to yours with raidtools-0.41, and upgrading it with the fixed raidtools, and it's working just fine after the upgrade: [root@hell /root]# cat /proc/mdstat Personalities : [linear] [raid0] [raid1] [raid5] [translucent] [lvm] read_ahead 256 sectors md0 : active raid1 sde1[1] sdc1[0] 1038400 blocks [2/2] [UU] unused devices: <none> [root@hell /root]# i've put out a new release of raidtools, raidtools-19981201-0.90.tar.gz to http://www.kernel.org/pub/linux/daemons/raid/alpha/, which includes this fix. Ingo
