On Sat, Oct 8, 2011 at 2:04 PM, Steve Brooks <steveb at mcs.st-and.ac.uk>wrote: > On Sat, 8 Oct 2011, Trey Dockendorf wrote: > > > I just upgraded my home KVM server to CentOS 6.0 CR to make use of the > > latest libvirt and now my RAID array with my VM storage is missing. It > > seems that the upgrade to mdadm-3.2.2 is the culprit. > > > > This is the output from mdadm when scanning that array, > > > > # mdadm --detail --scan > > ARRAY /dev/md0 metadata=imsm UUID=734f79cf:22200a5a:73be2b52:3388006b > > ARRAY /dev/md126 metadata=imsm UUID=3d135942:f0fad0b0:33255f78:29c3f50a > > mdadm(IMSM): Unsupported attributes : 40000000 > > mdadm: IMSM metadata loading not allowed due to attributes > incompatibility. > > mdadm(IMSM): Unsupported attributes : 40000000 > > mdadm: IMSM metadata loading not allowed due to attributes > incompatibility. > > ARRAY /dev/md127 container=/dev/md0 member=0 > > UUID=734f79cf:22200a5a:73be2b52:3388006b > > > > The error about IMSM shows up on google as something that happened to > Fedora > > users during a FC14->FC15 upgrade. > > > > The server itself isn't old, it's a Supermicro 2U with Dual Xeon 5400 > family > > of CPU. There are two RAIDs on this one controller...a RAID1 which still > > functions and a RAID5 which is the one that is unable to be seen. I > don't > > know what IMSM is for, but the only thing strange about that array is it > is > > 2.7TB so the BIOS configured it as two separate arrays, one as 2TB and > one > > as 700GB, but it was showing up to CentOS as a single volume. > > > > I downgraded to 3.2.1 , ran mdadm again and bam...it works, > > > > # mdadm --detail --scan > > ARRAY /dev/md0 metadata=imsm UUID=734f79cf:22200a5a:73be2b52:3388006b > > ARRAY /dev/md126 metadata=imsm UUID=3d135942:f0fad0b0:33255f78:29c3f50a > > ARRAY /dev/md127 container=/dev/md0 member=0 > > UUID=691f975d:6beecfd8:67b39886:b7ee7f6e > > > > Hopefully this can be fixed before this version makes it to 6.1, though > it's > > likely a problem for upstream RHEL as well. > > > > - Trey > > _______________________________________________ > > CentOS mailing list > > CentOS at centos.org > > http://lists.centos.org/mailman/listinfo/centos > > > > Hmm I recall seeing something like this on an "sl6" box. I think it needed > a "/etc/mdadm.conf" with som metadata id code.. I am pretty sure I fixed > it with > > mdadm --detail --scan >> /etc/mdadm.conf > > and a reboot. > > Steve > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > That's the problem, mdadm --detail --scan throws errors. After updating to mdadm-3.2.2 , and rebooting, the entry /dev/md126 was removed, likely because when I run it and don't pipe the output, it shows this... # mdadm --detail --scan ARRAY /dev/md0 metadata=imsm UUID=734f79cf:22200a5a:73be2b52:3388006b ARRAY /dev/md126 metadata=imsm UUID=3d135942:f0fad0b0:33255f78:29c3f50a mdadm(IMSM): Unsupported attributes : 40000000 mdadm: IMSM metadata loading not allowed due to attributes incompatibility. mdadm(IMSM): Unsupported attributes : 40000000 mdadm: IMSM metadata loading not allowed due to attributes incompatibility. ARRAY /dev/md127 container=/dev/md0 member=0 UUID=734f79cf:22200a5a:73be2b52:3388006b