From: NeilBrown <neilb@suse.de>
To: Veedar Hokstadt <veedar@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: mdadm -E won't examine loop back device, works ok on source disk
Date: Mon, 23 Apr 2012 07:58:16 +1000 [thread overview]
Message-ID: <20120423075816.6d21afe8@notabene.brown> (raw)
In-Reply-To: <CANb3qHeDF10CoRiteo_wwUSvGtpjcNWPh95xdatkFoY+GyAZJQ@mail.gmail.com>
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On Sun, 22 Apr 2012 17:00:04 -0400 Veedar Hokstadt <veedar@gmail.com> wrote:
> Consider a SATA drive /dev/sdb which is a member of an imsm RAID0 array...
>
> % sum /dev/sdb
> 25645 156290904
>
> The drive was imaged to a file without error and mounted as a loopback device...
>
> % sum /dev/loop2
> 25645 156290904
>
> The checksums match as expected. But I can not examine the loopback I get....
>
> % mdadm -E -v /dev/loop2
> mdadm: No md superblock detected on /dev/loop2.
>
> But I can examine the physical source drive /dev/sdb...
>
> % mdadm -E -v /dev/sdb
> /dev/sdb:
> Magic : Intel Raid ISM Cfg Sig.
> Version : 1.0.00
> Orig Family : e92a11d9
> Family : e92a11d9
> Generation : 00001608
> UUID : 25137636:2ff64e75:10ae5444:4e8f609b
> Checksum : e1237b20 correct
> MPB Sectors : 1
> Disks : 2
> RAID Devices : 1
>
> Disk01 Serial : 8068C3QVT
> State : active
> Id : 00010000
> Usable Size : 312577294 (149.05 GiB 160.04 GB)
>
> [Volume0]:
> UUID : 72acd5fa:35c5a901:995af79b:83a29de1
> RAID Level : 0
> Members : 2
> This Slot : 1
> Array Size : 625154048 (298.10 GiB 320.08 GB)
> Per Dev Size : 312577283 (149.05 GiB 160.04 GB)
> Sector Offset : 0
> Num Stripes : 1221004
> Chunk Size : 128 KiB
> Reserved : 0
> Migrate State : idle
> Map State : normal
> Dirty State : clean
>
> Disk00 Serial : 809BC541T
> State : active failed
> Id : 00000000
> Usable Size : 312577294 (149.05 GiB 160.04 GB)
>
> I'm trying to recover data from a failed RAID0.
> I can successfully reassemble the RAID0 from the image files using
> other proprietary recovery software.
> But I would like to get it working with mdadm if at all possible.
> Any ideas?
>
Try setting IMSM_NO_PLATFORM in the environment:
IMSM_NO_PLATFORM=1 mdadm -E -v /dev/loop2
or
export IMSM_NO_PLATFORM=1
mdadm -E -v /dev/loop2
I think this is fixed in more recent mdadm. You still need IMSM_NO_PLATFORM
to create or assemble an array, but not just to look at it.
NeilBrown
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next prev parent reply other threads:[~2012-04-22 21:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-22 21:00 mdadm -E won't examine loop back device, works ok on source disk Veedar Hokstadt
2012-04-22 21:58 ` NeilBrown [this message]
2012-04-23 4:46 ` Veedar Hokstadt
2012-04-23 5:04 ` NeilBrown
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