On 10/8/2011 3:14 PM, Trey Dockendorf wrote: > 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 > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos why bother with bios FAKERAID using PIO mode(effectively). Make a backup and redo using MD raid and turn off the bios raid. Then things will work correctly.