12 Sep
2016
12 Sep
'16
8:12 a.m.
I have a pair of 4mm DDS tapes from 1999 that I would like to recover.
I was able to read one with tar on a Debian (jessie) Linux system, but
the second gives an error.
The tape that I could read is a Sony with DDS markings and 4 bars next
to the DDS logo. It was written on an SGI computer. I was able to read
this with a simple tar -xvf /dev/st0 command.
The second tape is a 3M brand with DDS markings and 4 bars next to the
DDS logo. It also has 'Media Recognition System' and DD-90 written on
it. Here is the dialog and error:
root at T5400deb:/home/taylor/4mm_tar_1998# lsscsi
[0:0:4:0] disk codesrc SCSI2SD 4.2 /dev/sdc
[0:0:5:0] disk codesrc SCSI2SD 4.2 /dev/sdd
[0:0:6:0] tape ARCHIVE 4326XX 27871-XXX 0324 /dev/st0
[3:0:0:0] disk ATA WDC WD800JD-75MS 1E04 /dev/sda
[3:0:1:0] cd/dvd PLDS DVD+-RW DH-16A6S YD11 /dev/sr0
[4:0:0:0] disk ATA ST500DM002-1BD14 KC45 /dev/sdb
root at T5400deb:/home/taylor/4mm_tar_1998# mt -f /dev/st0 status
drive type = 114
drive status = 318767616
sense key error = 0
residue count = 0
file number = 0
block number = 0
root at T5400deb:/home/taylor/4mm_tar_1998# tar -xvf /dev/st0
tar: /dev/st0: Cannot read: Input/output error
tar: At beginning of tape, quitting now
tar: Error is not recoverable: exiting now
The tape drive is a Seagate CTD8000R-S with COMPAQ markings. There are 5
jumpers to configure the drive and one is for MRS which the jumper
config page I have says it is enabled (Default), however the pins are
missing for that option. What does that mean?
(None of the config jumpers were installed for the tape that I could
read) Is the 2nd tape just bad and can't be read? Or do I need a
slightly different tape drive?
Doug
12 Sep
12 Sep
3:05 p.m.
On 12/09/2016 16:12, Douglas Taylor wrote:
I have a pair of 4mm DDS tapes from 1999 that I would
like to recover.
I was able to read one with tar on a Debian (jessie) Linux system, but
the second gives an error.
The second tape is a 3M brand with DDS markings and 4
bars next to the
DDS logo. It also has 'Media Recognition System' and DD-90 written on
it. Here is the dialog and error:
root at T5400deb:/home/taylor/4mm_tar_1998# tar -xvf
/dev/st0
tar: /dev/st0: Cannot read: Input/output error
tar: At beginning of tape, quitting now
tar: Error is not recoverable: exiting now
(None of the config jumpers were installed for the
tape that I could
read) Is the 2nd tape just bad and can't be read? Or do I need a
slightly different tape drive?
It could be corrupt, or it could be byte-swapped, or it could have a
strange block size (especially a small one), or the heads might need
cleaned after reading the last tape, or it might not have any valid
data. Does the debian tape driver support byte-swapping? Or is there a
bs and non-bs version? You could try reading it with something like
dd if=/dev/rmt/tapedevice bs=20b conv=swab | tar tvf -
or whatever the debian tape device equivalent is. Does debian have some
equivalent to mt(1) to read/set the drive's blocksize and to move
forward and back along the tape?
Personally I hate DDS/DDS2/DDS3. I always had better luck with half
inch and even 8mm, and better still with DLT.
--
Pete
Pete Turnbull
4:35 p.m.
On 9/12/2016 6:05 PM, Pete Turnbull wrote:
On 12/09/2016 16:12, Douglas Taylor wrote:
I tried using different blocksizes with no luck. Debian does have the
mt command and I was able to use it to get the tape status, rewind and
was able to have it move the tape forward a number of records (not sure
what a record is)
#mt -f /dev/st0 fsr 10
worked. I seem to remember from those days that the brand of tape was
critical and that you could use audio tapes (DAT). I even tried od to
see if I could anything from the drive, no luck. I guess the cartridge
is bad.
Doug
I have a pair of 4mm DDS tapes from 1999 that I
would like to recover.
I was able to read one with tar on a Debian (jessie) Linux system, but
the second gives an error.
The second tape is a 3M brand with DDS markings
and 4 bars next to the
DDS logo. It also has 'Media Recognition System' and DD-90 written on
it. Here is the dialog and error:
root at T5400deb:/home/taylor/4mm_tar_1998# tar
-xvf /dev/st0
tar: /dev/st0: Cannot read: Input/output error
tar: At beginning of tape, quitting now
tar: Error is not recoverable: exiting now
(None of the config jumpers were installed for
the tape that I could
read) Is the 2nd tape just bad and can't be read? Or do I need a
slightly different tape drive?
It could be corrupt, or it could be byte-swapped, or it could have a
strange block size (especially a small one), or the heads might need
cleaned after reading the last tape, or it might not have any valid
data. Does the debian tape driver support byte-swapping? Or is there
a bs and non-bs version? You could try reading it with something like
dd if=/dev/rmt/tapedevice bs=20b conv=swab | tar tvf -
or whatever the debian tape device equivalent is. Does debian have
some equivalent to mt(1) to read/set the drive's blocksize and to move
forward and back along the tape?
Personally I hate DDS/DDS2/DDS3. I always had better luck with half
inch and even 8mm, and better still with DLT.
5:50 p.m.
On 09/12/16 16:35, Douglas Taylor wrote:
I tried using different blocksizes with no luck. Debian does have the
mt command and I was able to use it to get the tape status, rewind and
was able to have it move the tape forward a number of records (not sure
what a record is)
#mt -f /dev/st0 fsr 10
worked.
But as soon as it skipped anything, it would have rewound to the
beginning of the tape...
Rather than skipping records, I'd be curious about skipping the first
"file" in case you have an EOF mark at the start of the tape. You'd do
this with something like "mt -f /dev/nrst0 fsf 1"
The previous suggestion of using dd(1) is a good one, maybe you tried
the following and maybe not. Use the "mt rewind" command to make sure
you're at the beginning of the tape, then use dd with the "no rewind"
device, e.g. /dev/nrst0 or nst0. Hit it a couple times just in case
there were some bad writes at the start of the tape.
% mt -f /dev/st0 rewind
% dd if=/dev/nrst0 of=file-1.bin
% dd if=/dev/nrst0 of=file-2.bin
% dd if=/dev/nrst0 of=file-3.bin
...
You may just get zero-length files. Or, maybe you'll get past some
damage and get some of your data. Worth a shot, provided the tape isn't
shedding oxide...
I guess the cartridge is bad.
Possible. It also sounded like your problem tape might be DDS-1, while
your other tape might have been a later, higher capacity. Might that be
a problem for the drive you have? I haven't tried different density 4mm
tapes in drives in ages...
--S.
5:59 p.m.
What drive type are you trying to read that tape with? DD-90 is DDS-1 era
tape and DDS-4 drives (or newer) will not read it. Also hardware compression
might have something to do with it.
-----Original Message-----
From: Douglas Taylor
Sent: Monday, September 12, 2016 7:35 PM
To: cctalk at classiccmp.org
Subject: Re: Recovering 4mm tar tapes
On 9/12/2016 6:05 PM, Pete Turnbull wrote:
On 12/09/2016 16:12, Douglas Taylor wrote:
I tried using different blocksizes with no luck. Debian does have the
mt command and I was able to use it to get the tape status, rewind and
was able to have it move the tape forward a number of records (not sure
what a record is)
#mt -f /dev/st0 fsr 10
worked. I seem to remember from those days that the brand of tape was
critical and that you could use audio tapes (DAT). I even tried od to
see if I could anything from the drive, no luck. I guess the cartridge
is bad.
Doug
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
I have a pair of 4mm DDS tapes from 1999 that I
would like to recover.
I was able to read one with tar on a Debian (jessie) Linux system, but
the second gives an error.
The second tape is a 3M brand with DDS markings
and 4 bars next to the
DDS logo. It also has 'Media Recognition System' and DD-90 written on
it. Here is the dialog and error:
root at T5400deb:/home/taylor/4mm_tar_1998# tar
-xvf /dev/st0
tar: /dev/st0: Cannot read: Input/output error
tar: At beginning of tape, quitting now
tar: Error is not recoverable: exiting now
(None of the config jumpers were installed for
the tape that I could
read) Is the 2nd tape just bad and can't be read? Or do I need a
slightly different tape drive?
It could be corrupt, or it could be byte-swapped, or it could have a
strange block size (especially a small one), or the heads might need
cleaned after reading the last tape, or it might not have any valid data.
Does the debian tape driver support byte-swapping? Or is there a bs and
non-bs version? You could try reading it with something like
dd if=/dev/rmt/tapedevice bs=20b conv=swab | tar tvf -
or whatever the debian tape device equivalent is. Does debian have some
equivalent to mt(1) to read/set the drive's blocksize and to move forward
and back along the tape?
Personally I hate DDS/DDS2/DDS3. I always had better luck with half inch
and even 8mm, and better still with DLT.
2973
days inactive
2974
days old
4 comments
4 participants
participants (4)
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classiccmp＠crash.com -
dj.taylor4＠comcast.net -
pete＠dunnington.plus.com -
teoz＠neo.rr.com