FAQ
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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
ARRAY /dev/md126 metadata=imsm UUID=135942: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
UUIDs4f79cf: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
ARRAY /dev/md126 metadata=imsm UUID=135942:f0fad0b0:33255f78:29c3f50a
ARRAY /dev/md127 container=/dev/md0 member=0
UUIDi1f975d: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

Search Discussions

  • Steve Brooks at Oct 8, 2011 at 3:04 pm

    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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942:f0fad0b0:33255f78:29c3f50a
    ARRAY /dev/md127 container=/dev/md0 member=0
    UUIDi1f975d: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
  • Trey Dockendorf at Oct 8, 2011 at 3:14 pm

    On Sat, Oct 8, 2011 at 2:04 PM, Steve Brooks 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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942:f0fad0b0:33255f78:29c3f50a
    ARRAY /dev/md127 container=/dev/md0 member=0
    UUIDi1f975d: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf:22200a5a:73be2b52:3388006b
  • Ljubomir Ljubojevic at Oct 8, 2011 at 4:04 pm

    Vreme: 10/08/2011 09:14 PM, Trey Dockendorf pi?e:
    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...
    Have you tried "yum downgrade mdadm" ? and rebooting?
    --

    Ljubomir Ljubojevic
    (Love is in the Air)
    PL Computers
    Serbia, Europe

    Google is the Mother, Google is the Father, and traceroute is your
    trusty Spiderman...
    StarOS, Mikrotik and CentOS/RHEL/Linux consultant
  • William Warren at Oct 8, 2011 at 5:31 pm

    On 10/8/2011 3:14 PM, Trey Dockendorf wrote:
    On Sat, Oct 8, 2011 at 2:04 PM, Steve Brookswrote:
    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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942:f0fad0b0:33255f78:29c3f50a
    ARRAY /dev/md127 container=/dev/md0 member=0
    UUIDi1f975d: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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.
  • Trey Dockendorf at Oct 8, 2011 at 6:16 pm

    On Sat, Oct 8, 2011 at 4:31 PM, William Warren wrote:
    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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942:f0fad0b0:33255f78:29c3f50a
    ARRAY /dev/md127 container=/dev/md0 member=0
    UUIDi1f975d: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 UUIDs4f79cf:22200a5a:73be2b52:3388006b
    ARRAY /dev/md126 metadata=imsm UUID=135942: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
    UUIDs4f79cf: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.
    _______________________________________________
    CentOS mailing list
    CentOS at centos.org
    http://lists.centos.org/mailman/listinfo/centos

    I did the downgrade it it worked fine after.
  • Ljubomir Ljubojevic at Oct 8, 2011 at 8:23 pm

    Vreme: 10/09/2011 12:16 AM, Trey Dockendorf pi?e:
    On Sat, Oct 8, 2011 at 4:31 PM, William Warren<
    hescominsoon at emmanuelcomputerconsulting.com> wrote:
    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.
    I did the downgrade it it worked fine after.
    I just now realized that you have fakeraid (dmraid). That is very
    dangerous, because if MB dies, you might need to find another one with
    same chipset to make it work. On the other hand, Linux software RAID
    (mdadm). That way your RAID will work on any MB.

    So I also recommend William Warren's suggestion to convert as soon as
    possible. You can even use "RAID 10 - far" to gain 2 x read and 1 x
    write speed of normal disk while mirroring.


    --

    Ljubomir Ljubojevic
    (Love is in the Air)
    PL Computers
    Serbia, Europe

    Google is the Mother, Google is the Father, and traceroute is your
    trusty Spiderman...
    StarOS, Mikrotik and CentOS/RHEL/Linux consultant
  • Trey Dockendorf at Oct 9, 2011 at 12:21 am

    On Oct 8, 2011 7:23 PM, "Ljubomir Ljubojevic" wrote:
    Vreme: 10/09/2011 12:16 AM, Trey Dockendorf pi?e:
    On Sat, Oct 8, 2011 at 4:31 PM, William Warren<
    hescominsoon at emmanuelcomputerconsulting.com> wrote:
    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.
    I did the downgrade it it worked fine after.
    I just now realized that you have fakeraid (dmraid). That is very
    dangerous, because if MB dies, you might need to find another one with
    same chipset to make it work. On the other hand, Linux software RAID
    (mdadm). That way your RAID will work on any MB.

    So I also recommend William Warren's suggestion to convert as soon as
    possible. You can even use "RAID 10 - far" to gain 2 x read and 1 x
    write speed of normal disk while mirroring.


    --

    Ljubomir Ljubojevic
    (Love is in the Air)
    PL Computers
    Serbia, Europe

    Google is the Mother, Google is the Father, and traceroute is your
    trusty Spiderman...
    StarOS, Mikrotik and CentOS/RHEL/Linux consultant
    _______________________________________________
    CentOS mailing list
    CentOS at centos.org
    http://lists.centos.org/mailman/listinfo/centos
    Can anyone confirm or advise how to do partionable raid with mdadm in Centos
    6? I made a few attempts using methods from centos 5 with no success.
    Everytime I created md_d0 it did not contain any partions from the member
    disks.

    - Trey
  • Lucian at Oct 9, 2011 at 2:51 am

    On Sun, Oct 9, 2011 at 5:21 AM, Trey Dockendorf wrote:
    Can anyone confirm or advise how to do partionable raid with mdadm in Centos
    6? ?I made a few attempts using methods from centos 5 with no success.
    Everytime I created md_d0 it did not contain any partions from the member
    disks.
    I can advise not to do that, it always looked like an ugly hack to me.
    Just stick with the standard way. What I do is just create a small md
    raid for /boot (this needs to be raid1) and make everything else one
    big md raid with lvm on top. Works great for me and it's very flexible
    due to lvm and ext4 (that means on the fly filesystem resize among
    other things).
  • Ljubomir Ljubojevic at Oct 9, 2011 at 6:27 am

    Vreme: 10/09/2011 08:51 AM, Lucian pi?e:
    On Sun, Oct 9, 2011 at 5:21 AM, Trey Dockendorfwrote:
    Can anyone confirm or advise how to do partionable raid with mdadm in Centos
    6? I made a few attempts using methods from centos 5 with no success.
    Everytime I created md_d0 it did not contain any partions from the member
    disks.
    I can advise not to do that, it always looked like an ugly hack to me.
    Just stick with the standard way. What I do is just create a small md
    raid for /boot (this needs to be raid1) and make everything else one
    big md raid with lvm on top. Works great for me and it's very flexible
    due to lvm and ext4 (that means on the fly filesystem resize among
    other things).
    _______________________________________________
    CentOS mailing list
    CentOS at centos.org
    http://lists.centos.org/mailman/listinfo/centos
    +1

    --

    Ljubomir Ljubojevic
    (Love is in the Air)
    PL Computers
    Serbia, Europe

    Google is the Mother, Google is the Father, and traceroute is your
    trusty Spiderman...
    StarOS, Mikrotik and CentOS/RHEL/Linux consultant

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupcentos @
categoriescentos
postedOct 8, '11 at 2:48p
activeOct 9, '11 at 6:27a
posts10
users5
websitecentos.org
irc#centos

People

Translate

site design / logo © 2022 Grokbase