Comment 9 for bug 136804

This has been driving me slightly nuts since Fiesty's release (and it's persisted through Gutsy and doesn't seem to be fixed in Hardy beta's (up to 2.6.24-16) either). And yes, I know I should have raised it as a bug earlier, but I've just worked around it by booting into 2.6.20-12 which was the last kernel where it worked properly. My bad. I've an ASUS P5N-E SLI board (which I think uses the 680i chipset). Anyway, I've configured RAID-1 across two WD SATA drives for dual-booting into XP. Prior to 2.6.20-12 I was able to detect this fakeraid device with dmraid. Since 2.6.22, however, dmraid -ay gives the following message in /var/log/messages:

device-mapper: ioctl: error adding target to table

dmraid -tay works, however, so something's being detected:

nvidia_acihdbbb: 0 976773166 mirror core 2 131072 nosync 2 /dev/sda 0 /dev/sdb 0

I've Googled around a bit and some people are talking about it being a problem with duplicate UUIDs, which indeed there are on my system. blkid gives:

/dev/sda3: UUID="4EECF9B0ECF99287" TYPE="ntfs"
/dev/sdb3: UUID="4EECF9B0ECF99287" TYPE="ntfs"

but as the type is NTFS, there's no easy way to change this UUID.

I tried the same dmraid -ay on both the new Fedora 9 (which failed with the same error) and Knoppix 5.3.1, which uses 2.6.24 kernel - and it succeeded! So my very tentative assumption that it's a kernel bug introduced prior to 2.6.20 is wrong. udev? libdevmapper?

Would be very pleased to get any input or ideas. Any further info required, I'll be happy to post it here.