30 Dec
2022
30 Dec
'22
12:17 p.m.
This may be a larger conversation than I intend but how would you all
generally start if you ha backup tapes that you wanted to try and
read/restore?
Supposedly they're Amiga qic tapes. I'm a little worried about the
structural integrity of the tapes. Not knowing what software was used,
would this be a literal job for something like tar via a Linux system? Then
see if I can interpret the dump and sort out files afterwards?
I might see if a local group wants to help play with this effort since I
think I only have 1 drive in unknown condition.
30 Dec
30 Dec
5:01 p.m.
On 12/30/22 12:17, John Herron via cctalk wrote:
This may be a larger conversation than I intend but
how would you all
generally start if you ha backup tapes that you wanted to try and
read/restore?
Supposedly they're Amiga qic tapes. I'm a little worried about the
structural integrity of the tapes. Not knowing what software was used,
would this be a literal job for something like tar via a Linux system? Then
see if I can interpret the dump and sort out files afterwards?
I might see if a local group wants to help play with this effort since I
think I only have 1 drive in unknown condition.
The tape substrate itself, being mylar, is very durable, but it's toast
if stretched. Most likely, the internal tension band has either gone
slack or has broken and should be replaced, or else tape tangles can
result. Most importantly, details are necessary (what kind of carts,
what drive manufacturer and model, etc.) There are lots of potential
variations. To be frank, I hate the damned stuff.
--Chuck
--
--Chuck
Sent from my digital computer
5:37 p.m.
THere were certain tape manufacturers and plastic/metal clip marks and wear
patters that were typical of certain types of drives reading certain types
of tapes. Maybe high resolution photos of a few used tapes will reveal
clues. A tape ejected 30 times will have certain patterns of wear in
certain places. I have lots of different types of tapes, I am happy to
compare your used tape photos with anything I might have that would be
similar.
Not a guaranteed solution, but it might help narrow down candidate systems.
Bill
On Fri, Dec 30, 2022 at 8:01 PM Chuck Guzis via cctalk <
cctalk(a)classiccmp.org> wrote:
On 12/30/22 12:17, John Herron via cctalk wrote:
This may be a larger conversation than I intend
but how would you all
generally start if you ha backup tapes that you wanted to try and
read/restore?
Supposedly they're Amiga qic tapes. I'm a little worried about the
structural integrity of the tapes. Not knowing what software was used,
would this be a literal job for something like tar via a Linux system?
Then
see if I can interpret the dump and sort out
files afterwards?
I might see if a local group wants to help play with this effort since I
think I only have 1 drive in unknown condition.
The tape substrate itself, being mylar, is very durable, but it's toast
if stretched. Most likely, the internal tension band has either gone
slack or has broken and should be replaced, or else tape tangles can
result. Most importantly, details are necessary (what kind of carts,
what drive manufacturer and model, etc.) There are lots of potential
variations. To be frank, I hate the damned stuff.
--Chuck
--
--Chuck
Sent from my digital computer
6:04 p.m.
On 12/30/22 17:37, Bill Degnan via cctalk wrote:
THere were certain tape manufacturers and
plastic/metal clip marks and wear
patters that were typical of certain types of drives reading certain types
of tapes. Maybe high resolution photos of a few used tapes will reveal
clues. A tape ejected 30 times will have certain patterns of wear in
certain places. I have lots of different types of tapes, I am happy to
compare your used tape photos with anything I might have that would be
similar.
Not a guaranteed solution, but it might help narrow down candidate systems.
Bill
Heck, I'd just unspool a bit of the stuff, drop some Kyread on it and
have a gander with the old microscope. That can at least tell me how
many tracks are involved.
But being a quarter-inch cartridge leaves a lot of ground open. For
instance, what if these tapes are Iotaamat-formatted? A regular QIC
drive will have nothing to do with them. There were other manufacturers
(Cipher 525) comes to mind that do not use standard formatting
techniques. On some of the later 8mm Travan carts, the tape is
will-o'-the-wisp thin.
FWIW,
Chuck
5:02 p.m.
On 12/30/22 15:17, John Herron via cctalk wrote:
This may be a larger conversation than I intend but
how would you all
generally start if you ha backup tapes that you wanted to try and
read/restore?
Supposedly they're Amiga qic tapes. I'm a little worried about the
structural integrity of the tapes. Not knowing what software was used,
would this be a literal job for something like tar via a Linux system? Then
see if I can interpret the dump and sort out files afterwards?
It is unlikely that the tapes are in tar format, so tar on Linux won't
help. The chance that they are in tar format is much higher if they're
from Amix (Amiga Unix) instead of AmigaOS.
There is a better possibility that the tapes were created by BRU since
AmigaOS 2.x (and maybe later) included a version of that. BRU is now
Argest Backup, if you need to go down that road.
It is also possible that the tapes were created with any of the many
third-party backup applications that existed for AmigaOS.
In any case, using dd (not tar) on Linux to copy the tapes to disk to
"interpret" and "sort out files afterwards" is at least a starting
point.
Other list members are better qualified to comment on the physical
aspects of doing that without destroying the fragile old tapes.
9 Jan
9 Jan
11:25 a.m.
On 30/12/2022 20:17, John Herron via cctalk wrote:
This may be a larger conversation than I intend but
how would you all
generally start if you ha backup tapes that you wanted to try and
read/restore?
Supposedly they're Amiga qic tapes. I'm a little worried about the
structural integrity of the tapes. Not knowing what software was used,
would this be a literal job for something like tar via a Linux system? Then
see if I can interpret the dump and sort out files afterwards?
I might see if a local group wants to help play with this effort since I
think I only have 1 drive in unknown condition.
I'd start by figuring out what drive they were made with, and getting
one of those (and make sure it works in R/W mode with a scratch tape).
Then I'd image the tape with Tapeimgr
(<https://github.com/KBNLresearch/tapeimgr>) and see if I could figure
out what software was used. I've reverse-engineered a few, Retrospect
and one other, I think I uploaded it all to my Github.
Usually there's a bit of plaintext or a magic number in the files which
gives away the application which created them, and a quick Google search
will tell you what it was.
Cheers,
--
Phil.
philpem(a)philpem.me.uk
https://www.philpem.me.uk/
12:16 p.m.
Then I'd image the tape with Tapeimgr and see if I
could figure out
what software was used. I've reverse-engineered a few, Retrospect and
one other, I think I uploaded it all to my Github.
Phil's overall process is good, but you shouldn't use `dd` to image
tapes. It discards tape block length information, which is Bad <tm>.
This Tapeimgr tool just uses dd under the covers. (In some scenarios,
it _may_ be true that the tape blocks are all fixed length, but you may
only get one pass through the tape, so why risk it?)
https://github.com/brouhaha/tapeutils is probably a better choice. It
does not do as much work with metadata, but you can collect and record
such metadata in a sidecar file with no more effort than using Tapeimgr.
For QIC carts and the like, the little rubber bands often go sticky, and
may need to be carefully replaced. And definitely do testing of the
drive with a scratch monkey before risking the irreplaceable target
ones.
De
12:45 p.m.
On 1/9/23 12:16, Dennis Boone via cctalk wrote:
I've used the Linux scsitape utility (I think it's part of the mtx
package, but can't say offhand). It uses the generic SCSI interface
(/dev/sgxx) rather than the mt driver. Also, even if you use the dd
commands, be sure to install the mt-st package, as it has a bunch of
SCSI tape support logic in it that the default distro doesn't have.
FWIW,
Chuck
Then I'd
image the tape with Tapeimgr and see if I could figure out
what software was used. I've reverse-engineered a few, Retrospect and
one other, I think I uploaded it all to my Github.
Phil's overall process is good, but you shouldn't use `dd` to image
tapes. It discards tape block length information, which is Bad <tm>.
This Tapeimgr tool just uses dd under the covers. (In some scenarios,
it _may_ be true that the tape blocks are all fixed length, but you may
only get one pass through the tape, so why risk it?)
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7 comments
6 participants
participants (6)
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Bill Degnan -
Chuck Guzis -
Dennis Boone -
John Herron -
John-Paul Stewart -
Phil Pemberton