26 Nov
2019
26 Nov
'19
3:30 a.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.