Xref: utzoo comp.periphs:1357 comp.sys.sequent:110
Path: utzoo!attcan!uunet!unisoft!fai!ronc
From: ronc@fai.UUCP (Ronald O. Christian)
Newsgroups: comp.periphs,comp.sys.sequent
Subject: Re: 2 Gb cartridge tape drive
Message-ID: <1261@fai.UUCP>
Date: 13 Dec 88 20:30:58 GMT
References: <2400029@kailand> <1180@fai.UUCP> <50451@pyramid.pyramid.com>
Reply-To: ronc@fai.fai.com (Ronald O. Christian)
Organization: Fujitsu America, Inc.
Lines: 59

In article <50451@pyramid.pyramid.com> csg@pyramid.pyramid.com (Carl S. Gutekunst) writes:
>Followups directed to comp.periphs.
>
>[Doesn't anyone at Sequent read their own newsgroup? Sheesh.]

What he said.

>In article <1180@fai.UUCP> ronc@fai.fai.com (Ronald O. Christian) writes:
>- The 8mm drives are slow. You save a lot of storage space compared to 9-track
>  reels (something like 13 9-track tapes to 1 8mm cartridge), but backups take
>  about twice as long. Figure about two and a half hours per tape. Of course,
>  you'll have to change tapes 13 times less often....

This last part is the key.  There's this great big space between about
11:00 P.M. and 5:00 A.M. where our machines are very lightly used.  This
is an ideal time to do backups, but the problem is, I can't afford to
pay someone overtime to sit and watch the wheels turn.  The big plus about
getting 2 Gbytes on one tape is that you can arrange your backups so
that tape change is unnecessary.  Ergo, backups can be unattended.

>  [...] These are consumer quality, designed for use in Camcorders, with a
>  low duty cycle. (Say, a few hours a week.) Run continuously, ours died in
>  less than six weeks. Less use would give longer life, of course.

This makes sense.  But the issue with us is monthly level 0 backups.  They
take 24 nine-track tapes at present and require an operator to sit around
waiting to change them.  Assuming we do level 0 on the 8mm drive, we can
fit an entire dump on two tapes.  Surely two tapes a month isn't too high
a duty cycle?  My 8mm deck at home gets more use than that.

Our cost in 9 track tapes for daily incrementals is $9K per year.  For
that price we can buy an 8mm drive every year and still come out ahead!

>- Media integrity is *highly* dubious. These tapes are again consumer quality,
>  where all you have to do is get enough bits right to create a viewable TV
>  picture. Data storage is a whole 'nother story.

It's true that data storage is another story.  The data storage is digital
with error correction, whereas the camcorder signal is analog.  One would
think that digital recording techniques would be more robust.

In rec.video awhile back, someone asked if 9 track tape could be
used as video tape.  The consensus was that 9 track tape is poorer
quality than consumer video tape, not the other way around.

>I would not expect an 8mm
>  cartridge to hold usable data for more than a year or so.

Whyever for?  What's intrinsic about the 8mm tape that data would only
last a year?

Is this all speculation, or do you have hard data to back it up?


				Ron
-- 

      Ronald O. Christian (Fujitsu America Inc., San Jose, Calif.)
      {amdahl, pyramid, sun, unisoft, uunet}!fai!ronc -or- ronc@fai.com