From: NeilBrown <neilb@suse.de>
To: Khurram Hassan <kfhassan@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: Problem recovering failed Intel Rapid Storage raid5 volume
Date: Tue, 24 Jul 2012 08:13:49 +1000 [thread overview]
Message-ID: <20120724081349.41a30efa@notabene.brown> (raw)
In-Reply-To: <CAHijsZthcioN7YEcR2RGQcdeXJBVXpT8hniGZDbMxtXhVGM3vQ@mail.gmail.com>
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On Mon, 23 Jul 2012 21:54:24 +0500 Khurram Hassan <kfhassan@gmail.com> wrote:
> raid.status contents:
>
> /dev/sdb:
> Magic : Intel Raid ISM Cfg Sig.
> Version : 1.2.02
> Orig Family : 00000000
> Family : 6eb404da
> Generation : 002308e9
> Attributes : All supported
> UUID : 51c75501:a307676f:d2d6e547:dfcb2476
> Checksum : 06cf5ff9 correct
> MPB Sectors : 2
> Disks : 3
> RAID Devices : 1
>
> Disk01 Serial : 5VMLEGC6
> State : active
> Id : 00030000
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
>
> [VolumeData500:1]:
> UUID : a0865f28:57b7246b:ff43fa76:5531f5ca
> RAID Level : 5
> Members : 3
> Slots : [___]
> Failed disk : 1
> This Slot : 1 (out-of-sync)
> Array Size : 1953536000 (931.52 GiB 1000.21 GB)
> Per Dev Size : 976768264 (465.76 GiB 500.11 GB)
> Sector Offset : 0
> Num Stripes : 3815500
> Chunk Size : 128 KiB
> Reserved : 0
> Migrate State : idle
> Map State : failed
> Dirty State : clean
>
> Disk00 Serial : 9VM1GGJK:1
> State : active failed
> Id : ffffffff
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
>
> Disk02 Serial : 6VM4EGHC
> State : active
> Id : 00040000
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
You'll need to start out with
echo 1 > /sys/module/md_mod/parameters/start_dirty_degraded
otherwise creating the degraded raid5 won't work - I need to fix that.
Then
mdadm -C /dev/md/imsm -e imsm -n 2 /dev/sdb /dev/sdc
mdadm -C /dev/md0 -l5 -n3 -c 128 missing /dev/sdb /dev/sdc
so you create an IMSM container, then create the RAID5 inside that.
You should then check the filesystem to make sure it looks right.
If not, you might need to stop the arrays and start again, using a different
order of devices in the second command.
Good luck,
NeilBrown
> /dev/sdc:
> Magic : Intel Raid ISM Cfg Sig.
> Version : 1.2.02
> Orig Family : 00000000
> Family : 6eb404da
> Generation : 002308e9
> Attributes : All supported
> UUID : 51c75501:a307676f:d2d6e547:dfcb2476
> Checksum : 06cf5ff9 correct
> MPB Sectors : 2
> Disks : 3
> RAID Devices : 1
>
> Disk02 Serial : 6VM4EGHC
> State : active
> Id : 00040000
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
>
> [VolumeData500:1]:
> UUID : a0865f28:57b7246b:ff43fa76:5531f5ca
> RAID Level : 5
> Members : 3
> Slots : [___]
> Failed disk : 1
> This Slot : 2 (out-of-sync)
> Array Size : 1953536000 (931.52 GiB 1000.21 GB)
> Per Dev Size : 976768264 (465.76 GiB 500.11 GB)
> Sector Offset : 0
> Num Stripes : 3815500
> Chunk Size : 128 KiB
> Reserved : 0
> Migrate State : idle
> Map State : failed
> Dirty State : clean
>
> Disk00 Serial : 9VM1GGJK:1
> State : active failed
> Id : ffffffff
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
>
> Disk01 Serial : 5VMLEGC6
> State : active
> Id : 00030000
> Usable Size : 976768264 (465.76 GiB 500.11 GB)
>
>
> I hope you can figure it out as I am quite lost here.
>
> Thanks,
> Khurram
>
>
> On Mon, Jul 23, 2012 at 4:31 PM, Khurram Hassan <kfhassan@gmail.com> wrote:
> > raid.status contents:
> >
> > /dev/sdb:
> > Magic : Intel Raid ISM Cfg Sig.
> > Version : 1.2.02
> > Orig Family : 00000000
> > Family : 6eb404da
> > Generation : 002308e9
> > Attributes : All supported
> > UUID : 51c75501:a307676f:d2d6e547:dfcb2476
> > Checksum : 06cf5ff9 correct
> > MPB Sectors : 2
> > Disks : 3
> > RAID Devices : 1
> >
> > Disk01 Serial : 5VMLEGC6
> > State : active
> > Id : 00030000
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> >
> > [VolumeData500:1]:
> > UUID : a0865f28:57b7246b:ff43fa76:5531f5ca
> > RAID Level : 5
> > Members : 3
> > Slots : [___]
> > Failed disk : 1
> > This Slot : 1 (out-of-sync)
> > Array Size : 1953536000 (931.52 GiB 1000.21 GB)
> > Per Dev Size : 976768264 (465.76 GiB 500.11 GB)
> > Sector Offset : 0
> > Num Stripes : 3815500
> > Chunk Size : 128 KiB
> > Reserved : 0
> > Migrate State : idle
> > Map State : failed
> > Dirty State : clean
> >
> > Disk00 Serial : 9VM1GGJK:1
> > State : active failed
> > Id : ffffffff
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> >
> > Disk02 Serial : 6VM4EGHC
> > State : active
> > Id : 00040000
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> > /dev/sdc:
> > Magic : Intel Raid ISM Cfg Sig.
> > Version : 1.2.02
> > Orig Family : 00000000
> > Family : 6eb404da
> > Generation : 002308e9
> > Attributes : All supported
> > UUID : 51c75501:a307676f:d2d6e547:dfcb2476
> > Checksum : 06cf5ff9 correct
> > MPB Sectors : 2
> > Disks : 3
> > RAID Devices : 1
> >
> > Disk02 Serial : 6VM4EGHC
> > State : active
> > Id : 00040000
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> >
> > [VolumeData500:1]:
> > UUID : a0865f28:57b7246b:ff43fa76:5531f5ca
> > RAID Level : 5
> > Members : 3
> > Slots : [___]
> > Failed disk : 1
> > This Slot : 2 (out-of-sync)
> > Array Size : 1953536000 (931.52 GiB 1000.21 GB)
> > Per Dev Size : 976768264 (465.76 GiB 500.11 GB)
> > Sector Offset : 0
> > Num Stripes : 3815500
> > Chunk Size : 128 KiB
> > Reserved : 0
> > Migrate State : idle
> > Map State : failed
> > Dirty State : clean
> >
> > Disk00 Serial : 9VM1GGJK:1
> > State : active failed
> > Id : ffffffff
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> >
> > Disk01 Serial : 5VMLEGC6
> > State : active
> > Id : 00030000
> > Usable Size : 976768264 (465.76 GiB 500.11 GB)
> >
> >
> > I hope you can figure it out as I am quite lost here.
> >
> > Thanks,
> > Khurram
> >
> > On Mon, Jul 23, 2012 at 4:08 AM, NeilBrown <neilb@suse.de> wrote:
> >> On Sat, 21 Jul 2012 21:00:19 +0500 Khurram Hassan <kfhassan@gmail.com> wrote:
> >>
> >>> I have this 3 disk raid5 volumne on an Asus motherboard sporting an
> >>> Intel Rapid Storage chipset. The problem began when I noticed in
> >>> windows that one of the hard disks (the first one in the array) was
> >>> marked as failed in the Intel raid utility. I shutdown the system to
> >>> remove the hard disk and removed the cables for the faulty hard disk.
> >>> But I made a mistake and remove the cables for one of the working hard
> >>> disks. So when I booted, it showed the raid volume as failed. I
> >>> quickly shutdown the system and corrected the mistake. But it
> >>> completely hosed my raid volume. When I booted the system up again,
> >>> both of the remaining 2 hard disks were showed as offline.
> >>>
> >>> I read the raid recovery section in the wiki and installed ubuntu
> >>> 12.04 on a separate non-raid hard disk (after completely disconnecting
> >>> the offline raid5 volume). Then I reconnected the 2 hard disks and
> >>> booted ubuntu. Then I gave the following commands:
> >>>
> >>> 1) mdadm --examine /dev/sd[bc] > raid.status
> >>> 2) mdadm --create --assume-clean -c 128 --level=5 --raid-devices=3
> >>> /dev/md1 missing /dev/sdb /dev/sdc
> >>>
> >>> It gave the following output:
> >>> mdadm: /dev/sdb appears to be part of a raid array:
> >>> level=container devices=0 ctime=Thu Jan 1 05:00:00 1970
> >>> mdadm: /dev/sdc appears to be part of a raid array:
> >>> level=container devices=0 ctime=Thu Jan 1 05:00:00 1970
> >>> Continue creating array? y
> >>> mdadm: Defaulting to version 1.2 metadata
> >>> mdadm: array /dev/md1 started.
> >>>
> >>> But the raid volume is not accessible. mdadm --examine /dev/md1 gives:
> >>>
> >>> mdadm: No md superblock detected on /dev/md1.
> >>>
> >>> Worse, upon booting the system, the raid chipset message says the 2
> >>> hard disk are non-raid hard disks. Have I completely messed up the
> >>> raid volume? Is it not recoverable at all?
> >>
> >> Possibly :-(
> >>
> >> You had an array with Intel-specific metadata. This metadata is stored at
> >> the end of the device.
> >>
> >> When you tried to "--create" the array, you did not ask for intel metadata so
> >> you got the default v1.2 metadata. This metadata is stored at the beginning
> >> of the device (a 1K block, 4K from the start).
> >> So this would have over-written a small amount of filesystem data.
> >>
> >> Also when you --create an array, mdadm erases any other metadata that it
> >> finds to avoid confusion. So it will have erased the Intel metadata from the
> >> end.
> >>
> >> Your best hope is to recreate the array correctly with intel metadata. The
> >> filesystem will quite possibly be corrupted, but you might get some or even
> >> all of your data back.
> >>
> >> Can you post the "raid.status". That would help be certain we are doing the
> >> right thing.
> >> Something like
> >> mdadm --create /dev/md/imsm -e imsm -n 3 missing /dev/sdb /dev/sdc
> >> mdadm --create /dev/md1 -c 128 -l 5 -n 3 /dev/md/imsm
> >>
> >> might do it ... or might not. I'm not sure about creating imsm arrays with
> >> missing devices. Maybe you still list the 3 devices rather than just the
> >> container. I'd need to experiment. If you post the raid.status I'll see if
> >> I can work out the best way forward.
> >>
> >> NeilBrown
> >>
> --
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next prev parent reply other threads:[~2012-07-23 22:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHijsZt-CZ4BhjLU2sdWaGRtDa6bXjz0Bx+RRqoGRzvD6N6yvA@mail.gmail.com>
2012-07-21 16:00 ` Problem recovering failed Intel Rapid Storage raid5 volume Khurram Hassan
2012-07-22 23:08 ` NeilBrown
[not found] ` <CAHijsZvUoXcoee6kj84M9mYj=J-+9kSd8Zox2JCWrW+yhR_j1g@mail.gmail.com>
2012-07-23 16:54 ` Khurram Hassan
2012-07-23 22:13 ` NeilBrown [this message]
2012-07-24 7:14 ` Khurram Hassan
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