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* mdadm -E won't examine loop back device, works ok on source disk
@ 2012-04-22 21:00 Veedar Hokstadt
  2012-04-22 21:58 ` NeilBrown
  0 siblings, 1 reply; 4+ messages in thread
From: Veedar Hokstadt @ 2012-04-22 21:00 UTC (permalink / raw)
  To: linux-raid

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?

Regards,
V

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdadm -E won't examine loop back device, works ok on source disk
  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
  2012-04-23  4:46   ` Veedar Hokstadt
  0 siblings, 1 reply; 4+ messages in thread
From: NeilBrown @ 2012-04-22 21:58 UTC (permalink / raw)
  To: Veedar Hokstadt; +Cc: linux-raid

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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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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdadm -E won't examine loop back device, works ok on source disk
  2012-04-22 21:58 ` NeilBrown
@ 2012-04-23  4:46   ` Veedar Hokstadt
  2012-04-23  5:04     ` NeilBrown
  0 siblings, 1 reply; 4+ messages in thread
From: Veedar Hokstadt @ 2012-04-23  4:46 UTC (permalink / raw)
  To: NeilBrown; +Cc: linux-raid

Thanks for your reply but setting IMSM_NO_PLATFORM seems to have no effect...

% export IMSM_NO_PLATFORM=1
% echo $IMSM_NO_PLATFORM
1

% mdadm -V
mdadm - v3.2.3 - 23rd December 2011

% mdadm -E -v /dev/loop2
mdadm: No md superblock detected on /dev/loop2.

% export IMSM_NO_PLATFORM=""
% echo $IMSM_NO_PLATFORM

% mdadm -E -v /dev/loop2
mdadm: No md superblock detected on /dev/loop2.

And trying to assemble fails...
export IMSM_NO_PLATFORM=1
% mdadm --assemble /dev/md0 /dev/loop1 /dev/loop2
mdadm: Cannot assemble mbr metadata on /dev/loop1
mdadm: /dev/loop1 has no superblock - assembly aborted

Regards,
V

On Sun, Apr 22, 2012 at 5:58 PM, NeilBrown <neilb@suse.de> wrote:
> 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
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdadm -E won't examine loop back device, works ok on source disk
  2012-04-23  4:46   ` Veedar Hokstadt
@ 2012-04-23  5:04     ` NeilBrown
  0 siblings, 0 replies; 4+ messages in thread
From: NeilBrown @ 2012-04-23  5:04 UTC (permalink / raw)
  To: Veedar Hokstadt; +Cc: linux-raid

[-- Attachment #1: Type: text/plain, Size: 3798 bytes --]

On Mon, 23 Apr 2012 00:46:16 -0400 Veedar Hokstadt <veedar@gmail.com> wrote:

> Thanks for your reply but setting IMSM_NO_PLATFORM seems to have no effect...
> 
> % export IMSM_NO_PLATFORM=1
> % echo $IMSM_NO_PLATFORM
> 1
> 
> % mdadm -V
> mdadm - v3.2.3 - 23rd December 2011
> 
> % mdadm -E -v /dev/loop2
> mdadm: No md superblock detected on /dev/loop2.

Hmmmm....

Looks like you need
    IMSM_DEVNAME_AS_SERIAL=1
as well.  IMSM like to know the 'serial number' of each device and gets
confused when there isn't once ... and loop doesn't have serial numbers.

I should see if I can fix that.

Thanks
NeilBrown


> 
> % export IMSM_NO_PLATFORM=""
> % echo $IMSM_NO_PLATFORM
> 
> % mdadm -E -v /dev/loop2
> mdadm: No md superblock detected on /dev/loop2.
> 
> And trying to assemble fails...
> export IMSM_NO_PLATFORM=1
> % mdadm --assemble /dev/md0 /dev/loop1 /dev/loop2
> mdadm: Cannot assemble mbr metadata on /dev/loop1
> mdadm: /dev/loop1 has no superblock - assembly aborted
> 
> Regards,
> V
> 
> On Sun, Apr 22, 2012 at 5:58 PM, NeilBrown <neilb@suse.de> wrote:
> > 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
> >
> >
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


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^ permalink raw reply	[flat|nested] 4+ messages in thread

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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
2012-04-23  4:46   ` Veedar Hokstadt
2012-04-23  5:04     ` NeilBrown

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