24 Nov
2019
24 Nov
'19
10:39 p.m.
Historically important he says. The guy had creds.
https://twitter.com/textfiles/status/1198706617967095809?s=19
24 Nov
24 Nov
10:50 p.m.
I still have an exabyte scsi drive. You can read it with Linux. You just need a suitable
SCSI card. tar/cpio all work as expected.
From: "Richard Salz" <rich.salz(a)gmail.com>
To: "TUHS main list" <tuhs(a)minnie.tuhs.org>
Sent: Sunday, November 24, 2019 5:39:30 PM
Subject: [TUHS] Someone wants to use an exabyte
Historically important he says. The guy had creds.
https://twitter.com/textfiles/status/1198706617967095809?s=19
10:52 p.m.
Good luck with that. I had a 4/470 that had an exabyte, wheeled it out of
building 5 at Sun and into building 9 at SGI and the tapes wouldn't read
back.
On Sun, Nov 24, 2019 at 05:39:30PM -0500, Richard Salz wrote:
Historically important he says. The guy had creds.
https://twitter.com/textfiles/status/1198706617967095809?s=19
--
---
Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm
10:58 p.m.
On Sun, Nov 24, 2019 at 2:53 PM Larry McVoy <lm(a)mcvoy.com> wrote:
Good luck with that. I had a 4/470 that had an
exabyte, wheeled it out of
building 5 at Sun and into building 9 at SGI and the tapes wouldn't read
back.
We called them buffered dev-nulls.
TBH, that's what we called most tapes except for DLTs.
On Sun, Nov 24, 2019 at 05:39:30PM -0500, Richard Salz
wrote:
Historically important he says. The guy had
creds.
https://twitter.com/textfiles/status/1198706617967095809?s=19
--
---
Larry McVoy lm at mcvoy.com
http://www.mcvoy.com/lm
11:45 p.m.
I have two and they have found them to be spotting years later. I have
them in an FreeBSD box with SCSI.
On Sun, Nov 24, 2019 at 5:59 PM Rico Pajarola <rp(a)servium.ch> wrote:
On Sun, Nov 24, 2019 at 2:53 PM Larry McVoy <lm(a)mcvoy.com> wrote:
Sent from a handheld expect more typos than usual
Good luck with that. I had a 4/470 that had an
exabyte, wheeled it out of
building 5 at Sun and into building 9 at SGI and the tapes wouldn't read
back.
We called them buffered dev-nulls.
TBH, that's what we called most tapes except for DLTs.
On Sun, Nov 24, 2019 at 05:39:30PM -0500, Richard
Salz wrote:
-- Historically important he says. The guy had
creds.
https://twitter.com/textfiles/status/1198706617967095809?s=19
--
---
Larry McVoy lm at mcvoy.com
http://www.mcvoy.com/lm
25 Nov
25 Nov
1:41 a.m.
On Sun, 24 Nov 2019, Larry McVoy wrote:
Good luck with that. I had a 4/470 that had an
exabyte, wheeled it out
of building 5 at Sun and into building 9 at SGI and the tapes wouldn't
read back.
I've had all sorts of problems with those drives. Fortunately there was
an Exabyte agent not far from us, so they got a lot of our business.
-- Dave
1:42 a.m.
I just failed with a Sun DAT drive. Cable and card bought online,
recognized by the mt command, but all it does is eject tapes.
I am going to get a friend to come play with rubber bands and WD40 but
I'm not hopeful.
Bunch of data going to be rotting on tape.
-G
On Mon, Nov 25, 2019 at 11:41 AM Dave Horsfall <dave(a)horsfall.org> wrote:
On Sun, 24 Nov 2019, Larry McVoy wrote:
Good luck with that. I had a 4/470 that had an
exabyte, wheeled it out
of building 5 at Sun and into building 9 at SGI and the tapes wouldn't
read back.
I've had all sorts of problems with those drives. Fortunately there was
an Exabyte agent not far from us, so they got a lot of our business.
-- Dave
3:24 a.m.
So that sounds like a different problem. People correct me if I'm
wrong but the exabyte drives seemed to have a head alignment problem.
If you bumped the drive, the head moved and it stayed moved. So now
it can't read the tape because the head is offset. I have no data to
support this but I suspect someone that really understood these drives
might be able to move the head back in alignment.
On Mon, Nov 25, 2019 at 11:42:36AM +1000, George Michaelson wrote:
I just failed with a Sun DAT drive. Cable and card
bought online,
recognized by the mt command, but all it does is eject tapes.
I am going to get a friend to come play with rubber bands and WD40 but
I'm not hopeful.
Bunch of data going to be rotting on tape.
-G
On Mon, Nov 25, 2019 at 11:41 AM Dave Horsfall <dave(a)horsfall.org> wrote:
>
> On Sun, 24 Nov 2019, Larry McVoy wrote:
>
> > Good luck with that. I had a 4/470 that had an exabyte, wheeled it out
> > of building 5 at Sun and into building 9 at SGI and the tapes wouldn't
> > read back.
>
> I've had all sorts of problems with those drives. Fortunately there was
> an Exabyte agent not far from us, so they got a lot of our business.
>
> -- Dave
--
---
Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm
5:07 p.m.
On 11/24/19 7:24 PM, Larry McVoy wrote:
So that sounds like a different problem. People
correct me if I'm
wrong but the exabyte drives seemed to have a head alignment problem.
They are 8mm helical-head drives. they wouldn't go out of alignment by
bumping them, the worse would be the tape would lose tension if you
smacked the tensioning arms hard enough
They do have a lot of rubber parts inside.
Rollers crack and belts go soft. I have several dozen dead EX8200s from that.
I have a whole box of 8mm backup tapes that just came in, and a small
number of working drives. The Linux software I wrote to do 9 track tape recovery
from a SCSI 9 track drive works just fine on an Exabyte.
And I'm not offering to read Jason's mystery reels.
5:40 p.m.
A few years back, I decided to go through my stack of 8mm
Exabyte-written tapes... An early Exabyte 8200 2GB Exabyte drive was
useless. A 2/5G drive worked.
There were errors on one or two tapes. But each and every one was an
analog 8mm video tape, not a real data tape. And I was able to splice
the backup set enough so that whatever it was written with would be
happy enough to restore the data once pieced back together. A mix of
tar, and ufsbackup for the most part.
During this process, I bought an Exabyte Mammoth off eBay - didn't use
it much, but it read those old tapes just fine.
I was able to recover scads of personal stuff that I already had copies
of, along with a few dumps of the USENET systems I was using to serve as
a 3-modem BBS for USENET. And yes, sometimes, I go back into old backup
tapes to recover data I already have on disk. I hate bit-rot, I do
whatever I can to mitigate it.
art k.
PS: DAT 4mm tape drives, especially whatever Sun was using, were awful.
Around 50% of them I dealt with all got into a mode within the first
year where they would accept a tape, and just kick it back out right
away. Because they were under support, they were just replaced, so I
never looked into it hardware-wise.
On 11/25/2019 12:07 PM, Al Kossow wrote:
On 11/24/19 7:24 PM, Larry McVoy wrote:
So that sounds like a different problem. People
correct me if I'm
wrong but the exabyte drives seemed to have a head alignment problem.
They are 8mm
helical-head drives. they wouldn't go out of alignment by
bumping them, the worse would be the tape would lose tension if you
smacked the tensioning arms hard enough
They do have a lot of rubber parts inside.
Rollers crack and belts go soft. I have several dozen dead EX8200s from that.
I have a whole box of 8mm backup tapes that just came in, and a small
number of working drives. The Linux software I wrote to do 9 track tape recovery
from a SCSI 9 track drive works just fine on an Exabyte.
And I'm not offering to read Jason's mystery reels.
5:45 p.m.
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur Krewat wrote:
PS: DAT 4mm tape drives, especially whatever Sun was
using, were awful.
It's no secret that I enjoyed my years at Sun, but I can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
5:49 p.m.
Larry McVoy writes:
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur
Krewat wrote:
Well, I'd say even from an audio perspective DATs were crap. Just not a
good technology. Before DATs I used Beta decks with a PCM-601ES for
audio; was better than DAT probably because of the larger geometry. Same
reason that 9 track tapes last a long time - larger features.
In weird DAT tech, I have (although it's currently loaned out), one of the
SGI Archive Python drives that allows the DDS layer to be turned off so
that audio can be read and written directly.
PS: DAT 4mm tape drives, especially whatever Sun
was using, were awful.
It's no secret that I enjoyed my years at Sun, but I can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
6:34 p.m.
On 11/25/2019 12:45 PM, Larry McVoy wrote:
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur
Krewat wrote:
The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked
with them for the past 13 years, I can definitely say, are quit awesome.
DLT tapes and especially robots, well, it took HP about 5 years to get
the firmware right for a certain robot, the model of which, I don't
recall ...
art k.
PS: DAT 4mm tape drives, especially whatever Sun
was using, were awful.
It's no secret that I enjoyed my years at Sun, but I
can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
9:08 p.m.
I'm not an expert on mag tapes, but it makes sense to me that 9-track
tapes, where the tracks "line up" when the tape is wound onto a reel,
suffer more "print-through" than helical scan tapes, where tracks are not
aligned with those under them on a reel. I recall a suggestion that 9-track
tapes should be mounted and rewound once in a while, to reduce
print-through. We used Exabytes for disk backups for years, back when tape
capacity exceeded disk capacity. I doubt I'll see that again, but, as noted
I'm not an expert on mag tapes.
On Mon, Nov 25, 2019 at 1:35 PM Arthur Krewat <krewat(a)kilonet.net> wrote:
On 11/25/2019 12:45 PM, Larry McVoy wrote:
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur
Krewat wrote:
The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked
with them for the past 13 years, I can definitely say, are quit awesome.
DLT tapes and especially robots, well, it took HP about 5 years to get
the firmware right for a certain robot, the model of which, I don't
recall ...
art k.
PS: DAT 4mm tape drives, especially whatever Sun
was using, were awful.
It's no secret that I enjoyed my years at Sun, but I
can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
9:11 p.m.
Our problem wasn’t so much that the Exabyte tapes would go bad as the drives themselves
would keel over on a regular basis. It’s pretty much what drove us away from them.
The intelligence community did a lot of studies on archival storage devices. The
fundamental truth was to keep refreshed in the online domain rather than spending ages on
static media.
From: TUHS <tuhs-bounces(a)minnie.tuhs.org> On Behalf Of John P. Linderman
Sent: Monday, November 25, 2019 4:08 PM
To: Arthur Krewat <krewat(a)kilonet.net>
Cc: The Unix Heritage Society <tuhs(a)minnie.tuhs.org>
Subject: Re: [TUHS] Someone wants to use an exabyte
I'm not an expert on mag tapes, but it makes sense to me that 9-track tapes, where
the tracks "line up" when the tape is wound onto a reel, suffer more
"print-through" than helical scan tapes, where tracks are not aligned with those
under them on a reel. I recall a suggestion that 9-track tapes should be mounted and
rewound once in a while, to reduce print-through. We used Exabytes for disk backups for
years, back when tape capacity exceeded disk capacity. I doubt I'll see that again,
but, as noted I'm not an expert on mag tapes.
On Mon, Nov 25, 2019 at 1:35 PM Arthur Krewat <krewat(a)kilonet.net
<mailto:krewat@kilonet.net> > wrote:
On 11/25/2019 12:45 PM, Larry McVoy wrote:
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur
Krewat wrote:
The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked
with them for the past 13 years, I can definitely say, are quit awesome.
DLT tapes and especially robots, well, it took HP about 5 years to get
the firmware right for a certain robot, the model of which, I don't
recall ...
art k.
PS: DAT 4mm tape drives, especially whatever Sun
was using, were awful.
It's no secret that I enjoyed my years at Sun, but I
can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
9:30 p.m.
Fair enough, Ron. I recall that we had to replace Exabyte drives more often
than 9-track drives. On the other hand, I don't recall ever having an
Exabyte tape go bad, or being unable to restore a lost file (or entire
drive). Replacing a drive was chump change compared to losing a drive.
Plus, the Exabyte tapes were compact, and could easily have a paper label
inserted to indicate what was on them when hundreds were stored
side-by-side on a shelf. My labels were roundly mocked by Tom Limoncelli in
one of his Sysadmin books, but when a user came in wanting a file restored,
being able to identify which tape contained the most recent backup was no
laughing matter (to the user).
On Mon, Nov 25, 2019 at 4:12 PM <ron(a)ronnatalie.com> wrote:
Our problem wasn’t so much that the Exabyte tapes
would go bad as the
drives themselves would keel over on a regular basis. It’s pretty much
what drove us away from them. The intelligence community did a lot of
studies on archival storage devices. The fundamental truth was to keep
refreshed in the online domain rather than spending ages on static media.
*From:* TUHS <tuhs-bounces(a)minnie.tuhs.org> *On Behalf Of *John P.
Linderman
*Sent:* Monday, November 25, 2019 4:08 PM
*To:* Arthur Krewat <krewat(a)kilonet.net>
*Cc:* The Unix Heritage Society <tuhs(a)minnie.tuhs.org>
*Subject:* Re: [TUHS] Someone wants to use an exabyte
I'm not an expert on mag tapes, but it makes sense to me that 9-track
tapes, where the tracks "line up" when the tape is wound onto a reel,
suffer more "print-through" than helical scan tapes, where tracks are not
aligned with those under them on a reel. I recall a suggestion that 9-track
tapes should be mounted and rewound once in a while, to reduce
print-through. We used Exabytes for disk backups for years, back when tape
capacity exceeded disk capacity. I doubt I'll see that again, but, as noted
I'm not an expert on mag tapes.
On Mon, Nov 25, 2019 at 1:35 PM Arthur Krewat <krewat(a)kilonet.net> wrote:
On 11/25/2019 12:45 PM, Larry McVoy wrote:
On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur
Krewat wrote:
The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked
with them for the past 13 years, I can definitely say, are quit awesome.
DLT tapes and especially robots, well, it took HP about 5 years to get
the firmware right for a certain robot, the model of which, I don't
recall ...
art k.
PS: DAT 4mm tape drives, especially whatever Sun
was using, were awful.
It's no secret that I enjoyed my years at Sun, but I
can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel
and the QIC-150. Once it got to GB sized tapes, everything seemed
like crap.
9:38 p.m.
On Mon, 25 Nov 2019, Larry McVoy wrote:
It's no secret that I enjoyed my years at Sun,
but I can't defend these
drives, I had the same experience. When I look back on it, the only
tapes that I remember being reliable where the 9 track reel to reel and
the QIC-150. Once it got to GB sized tapes, everything seemed like
crap.
I see you've never enjoyed the thrills of "print through" on the 9-tracks,
nor the build-up of gunk (the then Australian Atomic Energy Commission had
a "tape cleaner" whereby the tape was basically run over a sharp blade).
And as for the QIC-150 drive that would occasionally fall back to what I
would call a QIC-75 when presented with media previously written at a
lower density... I recall that an EPROM upgrade fixed that.
-- Dave
6:29 p.m.
On Mon, Nov 25, 2019 at 10:07 AM Al Kossow <aek(a)bitsavers.org> wrote:
On 11/24/19 7:24 PM, Larry McVoy wrote:
IIRC, the main issue from back in the day was different densities on the
same form-factor tapes. So if you want to the same model 8mm drive, it
works, if you go to a different (older?) model, it wouldn't. Eg, going from
the 8500 -> 8200 caused problems due to data density issues. IIRC, you
could write low density data tapes on the 8500 for interchange with the
8200, but it wasn't the default on some platforms?
But it's been a long time and my memory is hazy... so long that Exabyte
went bankrupt, several new tenants tried to rent the old space, the
developer that bought it at the exabyte firesale wen bankrupt too and the
new developers that bought it have torn down the old Exabyte offices in
Boulder and replaced it with a set of luxury apartments... I could be
misremembering...
Warner
So that sounds like a different problem. People
correct me if I'm
wrong but the exabyte drives seemed to have a head alignment problem.
They are 8mm helical-head drives. they wouldn't go out of alignment by
bumping them, the worse would be the tape would lose tension if you
smacked the tensioning arms hard enough
They do have a lot of rubber parts inside.
Rollers crack and belts go soft. I have several dozen dead EX8200s from
that.
I have a whole box of 8mm backup tapes that just came in, and a small
number of working drives. The Linux software I wrote to do 9 track tape
recovery
from a SCSI 9 track drive works just fine on an Exabyte.
And I'm not offering to read Jason's mystery reels.
3:29 a.m.
On Mon, 25 Nov 2019, George Michaelson wrote:
I just failed with a Sun DAT drive. Cable and card
bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-)
Oh, if you must use one, make sure to use data-quality tapes, not the
cheaper media.
-- Dave
3:34 a.m.
New subject: Someone wants to use an exabyte [ really bulk erasing ]
Dave Horsfall writes:
On Mon, 25 Nov 2019, George Michaelson wrote:
I have several generations of these too. I also have several crates of
9-track tapes, QIC-24 tapes, QIC-150 tapes, and various generations of
DDS DAT tapes. I don't think that I have anything worth keeping on these
as I've transfered worthwhile stuff to newer media over time. Hard to
believe that the entire contents of a 9-track tape fit in a negligible
amount of memory these days.
The thing that's kept me from getting these out of my basement is that
I'd prefer to erase them first, just in case. Does anybody have experience
with a decent bulk tape eraser?
Jon
I just failed with a Sun DAT drive. Cable and
card bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-)
Oh, if you must use one, make sure to use data-quality tapes, not the
cheaper media.
-- Dave 
3:59 a.m.
New subject: Someone wants to use an exabyte [ really bulk erasing ]
I was successful with a Radio Shack VHS tape eraser on floppy disks. Should handle 8mm
and DDS as well as VHS. No guarantee of the quality of the wipe as far as data recovery
on the tapes because I never had a drive working long enough to test at home. Got DDS2
and exabyte jukeboxes but the drives crapped out.
Bill
William Pechter
________________________________
From: TUHS <tuhs-bounces(a)minnie.tuhs.org> on behalf of Jon Steinhart
<jon(a)fourwinds.com>
Sent: Sunday, November 24, 2019 10:34:05 PM
To: The Eunuchs Hysterical Society <tuhs(a)tuhs.org>
Subject: Re: [TUHS] Someone wants to use an exabyte [ really bulk erasing ]
Dave Horsfall writes:
On Mon, 25 Nov 2019, George Michaelson wrote:
I have several generations of these too. I also have several crates of
9-track tapes, QIC-24 tapes, QIC-150 tapes, and various generations of
DDS DAT tapes. I don't think that I have anything worth keeping on these
as I've transfered worthwhile stuff to newer media over time. Hard to
believe that the entire contents of a 9-track tape fit in a negligible
amount of memory these days.
The thing that's kept me from getting these out of my basement is that
I'd prefer to erase them first, just in case. Does anybody have experience
with a decent bulk tape eraser?
Jon
I just failed with a Sun DAT drive. Cable and
card bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-)
Oh, if you must use one, make sure to use data-quality tapes, not the
cheaper media.
-- Dave
3:25 p.m.
New subject: Someone wants to use an exabyte [ really bulk erasing ]
Somewhere in the basement, I have tape eraser that was recommended by one
of my brothers (who ran KHOU's Sports department for 30 years and it was a
piece of gear they used all the time for professional video tapes). I
haven't used it much, but I have used it for 9-tracks and seems to have
worked. FWIW: I got it here at a (in)famous local electronics place near
MIT (Eli Hefferon and Sons - 'A Nerdi Knight Holy Place') I must have
gotten it in the early/mid 1980s for about $75, I remember it was much more
expensive than the Radio Shack thing - but my bro said it really worked.
At the time I was doing some consulting for a NYC law firm and I had to
document to the courts that all the data I had been delivered was properly
destroyed. They were satisfied and never heard anything more about it.
It seems to have erased everything have had near it when it on. In fact, I
was always a little worried that it will erase unintended stuff too when I
use it. It hums and vibrates on the table and you are supposed to move the
tape horizontal to it and make circular motions over it. I had taken my
watch and wedding ring off the first time I ever tried it and it moved my
watch from a table about 3 feet away. I was pretty impressed.
On Sun, Nov 24, 2019 at 10:59 PM William Pechter <pechter(a)gmail.com> wrote:
I was successful with a Radio Shack VHS tape eraser on
floppy disks.
Should handle 8mm and DDS as well as VHS. No guarantee of the quality of
the wipe as far as data recovery on the tapes because I never had a drive
working long enough to test at home. Got DDS2 and exabyte jukeboxes but
the drives crapped out.
Bill
William Pechter
------------------------------
*From:* TUHS <tuhs-bounces(a)minnie.tuhs.org> on behalf of Jon Steinhart <
jon(a)fourwinds.com>
*Sent:* Sunday, November 24, 2019 10:34:05 PM
*To:* The Eunuchs Hysterical Society <tuhs(a)tuhs.org>
*Subject:* Re: [TUHS] Someone wants to use an exabyte [ really bulk
erasing ]
Dave Horsfall writes:
On Mon, 25 Nov 2019, George Michaelson wrote:
I have several generations of these too. I also have several crates of
9-track tapes, QIC-24 tapes, QIC-150 tapes, and various generations of
DDS DAT tapes. I don't think that I have anything worth keeping on these
as I've transfered worthwhile stuff to newer media over time. Hard to
believe that the entire contents of a 9-track tape fit in a negligible
amount of memory these days.
The thing that's kept me from getting these out of my basement is that
I'd prefer to erase them first, just in case. Does anybody have experience
with a decent bulk tape eraser?
Jon
I just failed with a Sun DAT drive. Cable and
card bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-)
Oh, if you must use one, make sure to use data-quality tapes, not the
cheaper media.
-- Dave
5:13 p.m.
New subject: Someone wants to use an exabyte [ really bulk erasing ]
The radio shack 43-232's will take care of things, they just have limited
duty-cycles
There are lots on eBay
Sometimes the pro ones for 1/2" tape show up that are about 12" square with a
timer
I have one, but I've looked at the analog output of a 1/2" tape drive after a
pass with
the RS, and there isn't much left.
On 11/25/19 7:25 AM, Clem Cole wrote:
Somewhere in the basement, I have tape eraser that was
recommended by one of my brothers
4:53 a.m.
New subject: Someone wants to use an exabyte [ really bulk erasing ]
On Sun, 24 Nov 2019, Jon Steinhart wrote:
The thing that's kept me from getting these out
of my basement is that
I'd prefer to erase them first, just in case. Does anybody have
experience with a decent bulk tape eraser?
I had a bunch of tapes (some strange type for an early "home computer"
belonging to my deceased father) that my brother wanted to bulk-erase, as
they contained my father's business details etc.
Now, it transpired that one of my clients at the time happened to be a
certain department of the police, that specialised in, err, phone-tapping
in real time i.e. a known drug-dealer would use the phone, an alarm would
go off, and away went the tape recorders (both cassette and mag) along
with humans listening in. I'm afraid that I can't say much more than
that...
Anyway, into their bulk eraser went the tapes, and out came blanks. This
was confirmed when said brother decided to read a tape, and found that he
couldn't :-)
So, if you happen to know someone in that area...
-- Dave
3:36 a.m.
On Mon, Nov 25, 2019 at 02:29:02PM +1100, Dave Horsfall wrote:
On Mon, 25 Nov 2019, George Michaelson wrote:
Really? Are we talking about those tapes that looked like reel to reel
audio tapes but bigger? Like this?
https://www.canajunfinances.com/wp-content/uploads/2013/04/9-Track-Tape.jpg
Because those are 1000x more reliable than an exabyte tape, they just
worked. Pretty much no matter what, you can spool up that tape and it
will read. 30 years later it will read.
Exabyte won't read 20 minutes later.
I just failed with a Sun DAT drive. Cable and card
bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-)
10:34 p.m.
On Sun, 24 Nov 2019, Larry McVoy wrote:
Yes.
They're
worse than 9-track tapes, and that's saying something :-)
Really? Are we talking about those tapes that looked like reel to reel
audio tapes but bigger? Like this?
https://www.canajunfinances.com/wp-content/uploads/2013/04/9-Track-Tape.jpg Because those are 1000x more reliable than an exabyte
tape, they just
worked. Pretty much no matter what, you can spool up that tape and it
will read. 30 years later it will read.
Please read my reply about print-through, build-up of gunk, etc. I'd be
surprised if a 9-track was 100% readable 30 years on.
Exabyte won't read 20 minutes later.
Bit of an exaggeration, but yes in principle.
-- Dave
26 Nov
26 Nov
1:38 a.m.
I deleted the original message, but I happened to find an Exabyte EX8505 SCSI drive in the
basement just now…
Centronics style SCSI sconnectors. I might have cables somewhere.
Pretty sure I used it in the ‘0’s from a linux system or laptop, since I’ve never had a
Sun.
Who wanted one?
-Larry
25 Nov
25 Nov
10:57 p.m.
On Sun, 24 Nov 2019 at 22:37, Larry McVoy <lm(a)mcvoy.com> wrote:
On Mon, Nov 25, 2019 at 02:29:02PM +1100, Dave
Horsfall wrote:
I think that certain amount of the reliability issue, as far as both the
tapes and the drives are concerned, has to do with scale. Those 8mm
Exabyte tapes (DDS tapes, too) are much thinner and hence more easily
damaged than a large 9 track reel. If thin tape in a cartridge gets fouled
up past a certain point, forget it, there's no salvaging that cartridge.
If open reel tape gets damaged and you really need what's on it you can
hope that the mechanism can read past the damaged part (a possibility), or
as a last resort you could make a careful splice and then attempt to
retrieve the rest of the data.
One of the other issues, totally independent of tape, is the rubber chosen
by the manufacturers for the drive belts and rollers. Some rubber, stored
properly, will still be in usable shape after twenty or thirty years. The
rubber on the rollers of my Sun QIC-150 drive? A goopy mess which rendered
the drive useless as well as a tape.
But yeah, about 15 years ago I was asked to retrieve some data from Exabyte
8200 tapes that had been written 10 years prior. I went through three
drives and countless hours of frustration just to read a half-dozen tapes
with some really important information on them. "Archive format" indeed.
-Henry
On Mon, 25 Nov 2019, George Michaelson wrote:
Really? Are we talking about those tapes that looked like reel to reel
audio tapes but bigger? Like this?
https://www.canajunfinances.com/wp-content/uploads/2013/04/9-Track-Tape.jpg
Because those are 1000x more reliable than an exabyte tape, they just
worked. Pretty much no matter what, you can spool up that tape and it
will read. 30 years later it will read.
Exabyte won't read 20 minutes later.
I just failed with a Sun DAT drive. Cable and card
bought online,
recognized by the mt command, but all it does is eject tapes.
They're worse than 9-track tapes, and that's saying something :-) 
27 Nov
27 Nov
7:31 p.m.
At 04:52 PM 11/24/2019, Larry McVoy wrote:
Good luck with that. I had a 4/470 that had an
exabyte, wheeled it out of
building 5 at Sun and into building 9 at SGI and the tapes wouldn't read
back.
I jumped in on that Twitter thread when I saw it.
Two years ago or so, I attempted to read a couple dozen old backup tapes from the mid
1990s. Half were Archive Python DDS-2 era, written on two different drives that I still
had, as 'tar' tapes from SGI workstations. The other half were Exabyte 8500 8mm,
some 'tar' from SGI and Linux and Amiga, some
Windows NTBACKUP. I set up a fresh Linux box with an Adaptec SCSI card.
I couldn't get any of the DDS-2 to read, either on the original hardware that wrote
them, or on a newer STD28000N drive I bought on eBay, a pull from an old Apple server. I
could write new tapes on the drive, just couldn't read any old ones. My attempts
included reading some tapes I know I'd received from other people (that is, written
on other drives) that I know I had been able to read on this hardware back in the day.
They wouldn't read, either.
On the other hand, I could read the majority of the Exabytes, even on the original drive I
had retained, as well as another I'd bought used in the early 2000s. Some had bad
blocks here and there.
The tougher task was trying to find contemporary tools that could process the data stream
from an old NTBACKUP, especially a stream with corruption from missing chunks, as I
wasn't in the mood to try to rebuild an NT machine with SCSI to let NTBACKUP deal
with the drive directly, and I think it would probably fail harder on direct drive
errors.
The Amiga-made 'tar' archives were readable by 'tar' but the file time
stamps weren't right when burst under Linux. I didn't debug that yet.
- John
8:56 p.m.
On 11/27/2019 2:31 PM, John Foust wrote:
I couldn't get any of the DDS-2 to read, either
on the original hardware that wrote them, or on a newer STD28000N drive I bought on eBay,
a pull from an old Apple server. I could write new tapes on the drive, just couldn't
read any old ones. My attempts included reading some tapes I know I'd received from
other people (that is, written on other drives) that I know I had been able to read on
this hardware back in the day. They wouldn't read, either.
That sounds like a
block size issue. Usually telling dd to use a larger
block than the tape has is fine, but if the default is smaller than
what's on the tape, it'll fail.
Depending on the drive firmware, the OS support for that particular
drive, etc, you may or may not get warnings or errors that actually mean
anything.
A long time ago, I attempted to read some 9-track TOPS-10 tapes using a
Sun and a 6250 BPI capable tape drive. Nothing would read, it looked
like there were actually no files on the tape whatsoever. So I gave up,
but kept the tapes because they contained a lot of personal stuff I had
done in high school and a few years after.
Years later, I got my hands on a Sun3/280 with 9-track tape drive, and
attempted to read them again. Same thing, looked like there were no
files on the tape. Started increasing the block size, and VOILA, got data.
Very odd circumstance, but block size has a lot to do with trying to
read tapes. QIC-150, 8mm, 9-track, I've run into it a lot.
art k.
9:25 p.m.
On Wed, 27 Nov 2019, Arthur Krewat wrote:
[...]
Very odd circumstance, but block size has a lot to do
with trying to
read tapes. QIC-150, 8mm, 9-track, I've run into it a lot.
Yep; you tended to use the biggest block size you could, in order to cut
down on the number of inter-record gaps (and of course, efficiency).
-- Dave
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31 comments
18 participants
participants (18)
-
Al Kossow -
Arthur Krewat -
Clem Cole -
Dave Horsfall -
Dennis Boone -
George Michaelson -
Henry Bent -
Jim Capp -
John Foust -
John P. Linderman -
Jon Steinhart -
Larry McVoy -
Lawrence Stewart -
Richard Salz -
Rico Pajarola -
ron＠ronnatalie.com -
Warner Losh -
William Pechter