17 Jun
2014
17 Jun
'14
1:12 a.m.
I'm trying to recover some data stored on an HP SureStore T20 SCSI tape
drive on a Travan TR5 tape. The tape is a QIC-3220-MC format.
The data was written using either HP's Colorado Backup II software or
Yosemite Technologies TapeWare 6.20 SP3B, or even Backup Exec. I
believe it was TapeWare. It was done on either a Win98 machine or a
Windows 2000 machine.
When I pull the header information off the tape, I see this
http://pastebin.com/xn837e0w
HEADERQIC113 volume name of Disaster Recovery 00001, Arcada Software,
INC. vendor.
I'm attempting the recovery in linux, using ddrescue on the /dev/nst0
device. The first 660MB is readable but of course the files still need
extracted from the raw tape dump.
Once an error is encountered, the HP's firmware takes the SCSI device
basically off-line, and tries multiple passes, resync's the tape, tries
again, and basically goes unresponsive. I'd love to go "raw" and just
have the drive report a straight-up error, and move past it on the tape,
because there could be more readable data stored later.
Even if I'm able to extract a large portion of the data, there's still
the issue of how to handle this format. I've found the QIC113 spec
online, and it doesn't seem impossible, but obviously it might be nice
if there were pre-made tools out there to deal with this.
Anyone familiar with any tools that can manipulate this file format? Is
it possible to disable the "intelligent" error handling of the drive to
just read it in a raw manner?
Thanks,
Keith
17 Jun
17 Jun
2:16 a.m.
On 06/16/2014 10:12 PM, Keith Monahan wrote:
Anyone familiar with any tools that can manipulate
this file format? Is
it possible to disable the "intelligent" error handling of the drive to
just read it in a raw manner?
Well, it's been a long time since I fooled with DDS and Travan tapes,
but I do have the OEM Manual for the HP 35470/80A DDS drive, so it may
shed some light.
When you encounter the error, how long do you give the drive to recover?
Do you have the sense bytes from the read operation?
On the DDS drive, the error recovery can be quite lengthy, upwards of 6
minutes. If it fails, the manual is unclear if you can simply skip to
the next block or not, but that might be worth a try (use the SCSI
LOCATE command).
HP acquired the Colorado line, so there may well be OEM manuals around
from Colorado that better describe the operation of
your particular unit.
--Chuck
10:18 a.m.
On 6/17/2014 2:16 AM, Chuck Guzis wrote:
Well, it's been a long time since I fooled with
DDS and Travan tapes,
but I do have the OEM Manual for the HP 35470/80A DDS drive, so it may
shed some light.
When you encounter the error, how long do you give the drive to recover?
Do you have the sense bytes from the read operation?
On the DDS drive, the error recovery can be quite lengthy, upwards of 6
minutes. If it fails, the manual is unclear if you can simply skip to
the next block or not, but that might be worth a try (use the SCSI
LOCATE command).
Chuck,
Thanks for the reply.
It turns out two tapes "gave up the ghost" as I was trying to read them.
Both made a horrible noise, and one of the tapes is clearly now damaged.
I was successfully able to read a full tape last night, but I'm still
stuck with the problem of how to extract the files from the image. I
believe that the resulting tape image would be a .qic file, so maybe if
i can find something that reads those vs wanting to read via an attached
device.
FWIW, I'm working mostly at the block level and treating it as a file,
so I'm way above SCSI commands, for instance. It might be moot now,
anyways.
thanks,
Keith
11:48 a.m.
On 06/17/2014 07:18 AM, Keith Monahan wrote:
It turns out two tapes "gave up the ghost"
as I was trying to read them.
Both made a horrible noise, and one of the tapes is clearly now damaged.
This isn't going to save the two damaged tapes, but when you get that
telltale squeal, the procedure is to "bake" any other tapes at between
130-140F for several hours.
Google "sticky shed" WRT audio tapes, for example. Same goes for
floppies. I have a DIY "oven" with about a cubic foot of space inside
with a slow-speed fan and a PID controller operating a 75V incandescent
as a heater. It holds the temperature to better than +/- 2F. It works
pretty well.
It's becoming increasingly necessary to handle floppies this way also.
I was successfully able to read a full tape last
night, but I'm still
stuck with the problem of how to extract the files from the image. I
believe that the resulting tape image would be a .qic file, so maybe if
i can find something that reads those vs wanting to read via an attached
device.
There were many backup file formats, so I can't really help you there.
I pretty much do recovery from scratch and roll my own decoding routines.
Good luck.
--Chuck
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