Backup Central

A colleage accidentally labelled a physically write protected tape which I have
loaded for a restore.  The tape now shows 0% utilised.  Scanning the tape will
come up with an "fn 2 rn 0 read error More data is available" error.

I tried scanner -f 3 it didn't work, neither did -f 4 -f 5 etc.

Correct me if I'm wrong but it doesn't appear like a block size issue as the
tape block size is 128k and the device maximum block size exceeds that.  I would
like to believe that the data is still in there because the tape is physically
write protected.


\\.\Tape0:
        Media Capacity  = 37.25GByte
        Media Remaining = 28.65GByte
        Media Blocksize = 0
        Media Partition Count = 1
        Media is not write protected
        default blocksize = 65536
        maximum blocksize = 524288
        minimum blocksize = 1
        MaximumPartitionCount = 1
        Partition = 0
        ...


Thanks!
Jonathan





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Jonathan,

On 01/09/2010, at 19:07 , Jonathan Natividad wrote:

A colleage accidentally labelled a physically write protected tape which I have
loaded for a restore. The tape now shows 0% utilised. Scanning the tape will
come up with an "fn 2 rn 0 read error More data is available" error.

I tried scanner -f 3 it didn't work, neither did -f 4 -f 5 etc.

Correct me if I'm wrong but it doesn't appear like a block size issue as the
tape block size is 128k and the device maximum block size exceeds that. I would
like to believe that the data is still in there because the tape is physically
write protected.

If it was physically write protected at the time it was relabelled, then NetWorker would have deleted the old media database entry and be expecting something different on the tape.

Likely you could delete the current volume label from the media database (i.e., nsrmm -d volumeName), then run a scanner command against the volume to repopulate the original media database entries for it. That's what I've done in the past when customers have had this issue.

Cheers,

Preston.

--
Preston de Guise

http://nsrd.info/blog NetWorker Blog
http://www.enterprisesystemsbackup.com "Enterprise Systems Backup and Recovery: A corporate insurance policy"






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Sorry Jonathan but this line from your post says it all :

\\.\Tape0:
Media Capacity = 37.25GByte
Media Remaining = 28.65GByte
Media Blocksize = 0
Media Partition Count = 1
--> Media is not write protected

Looks like you'll need to send the tape to a data recovery specialist if you need to get the data back

Regards

Jock Howie


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In regard to: Re: [Networker] Labelled write protected tape, Preston de...:

If it was physically write protected at the time it was relabelled, then
NetWorker would have deleted the old media database entry and be
expecting something different on the tape.

Are you certain, Preston? Doesn't the delete happen only if (and after)
the label succeeds?

Tim
--
Tim Mooney Tim.Mooney < at > ndsu.edu
Enterprise Computing & Infrastructure 701-231-1076 (Voice)
Room 242-J6, IACC Building 701-231-8541 (Fax)
North Dakota State University, Fargo, ND 58105-5164


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In regard to: [Networker] Labelled write protected tape, Jonathan Natividad...:

A colleage accidentally labelled a physically write protected tape which
I have loaded for a restore.

That's not possible. NetWorker would have given you an error message if
the label had failed. The label could NOT have succeeded if the tape
was physically write protected.

Part of your data has been destroyed. There's likely a lot more that's
still on the tape, but you won't be able to get at it (short of some
clever tricks that might just make things worse) using the tape drives
you have. You'll need to get a data recovery service involved if you
really do need that data.

Tim
--
Tim Mooney Tim.Mooney < at > ndsu.edu
Enterprise Computing & Infrastructure 701-231-1076 (Voice)
Room 242-J6, IACC Building 701-231-8541 (Fax)
North Dakota State University, Fargo, ND 58105-5164


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Thanks for all your inputs. But from most of your replies, it appears that
we can no longer recover the data on the tape without the services of a
recovery specialist. By the way, the tape labeling failed because of the
write protect. However, it appears that the physical write protect switch
won't "really protect" us from accidents in the sense that it
doesn't "completely" write protect the whole tape contents. Which, I think
should not be the case, because then the physical write protect switch
would be useless. And because the label failed, I would think that only
the "headers" (or something like that) was damaged and that there might be
a way to scan the contents. Hopefully someone out there has some fancy
command I can run. Fingers crossed.

Seems like I posted the output of the wrong tape. Here's the correct one.

X:\>mt -f \\.\Tape2 status
\\.\Tape2:
Media Capacity = 37.25GByte
Media Remaining = 0
Byte
Media Blocksize = 0
Media Partition Count = 1
Media is write protected
default blocksize = 65536
maximum blocksize = 524288
minimum blocksize = 1
MaximumPartitionCount = 1
Partition = 0
Logical block position = 0
EOTWarningZoneSize = 0
CompressionEnabled
...

Here's an output of the scanner command.

X:\>scanner -mv -f 3 -r 2 \\.\Tape2
8909:scanner: using '\\.\Tape2' as the device name
9000:scanner: \\.\Tape2: opened for reading
9003:scanner: \\.\Tape2: rewinding
8968:scanner: Reading the label...
8969:scanner: Reading the label done
8936:scanner: scanning LTO Ultrium-3 tape 100026L3 on \\.\Tape2
8937:scanner: volume id 4268743240 record size 131072
created 2/08/10 20:32:56 expires 2/08/12 20:32:56
8939:scanner: LTO Ultrium-3 tape 100026L3 already exists in the media index
8973:scanner: setting position from fn 0, rn 1 to fn 3, rn 2
39077:scanner: error, fsr 1 (read): More data is available.

8770:scanner: fn 3 rn 2 read error More data is available.

9000:scanner: \\.\Tape2: opened for reading
8770:scanner: fn 3 rn 2 read error More data is available.

9000:scanner: \\.\Tape2: opened for reading
8761:scanner: done with LTO Ultrium-3 tape 100026L3

9003:scanner: \\.\Tape2: rewinding

X:\>



On Thu, 2 Sep 2010 00:07:48 +1200, Howie Jock <Jock.Howie < at > NZPOST.CO.NZ>
wrote:

Sorry Jonathan but this line from your post says it all :

\\.\Tape0:
Media Capacity = 37.25GByte
Media Remaining = 28.65GByte
Media Blocksize = 0
Media Partition Count = 1
--> Media is not write protected

Looks like you'll need to send the tape to a data recovery specialist if
you need to get the data back

Regards

Jock Howie

<snip!>


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