2 Gb cartridge tape drive

[Carl S. Gutekunst]

Followups directed to comp.periphs.

[Doesn't anyone at Sequent read their own newsgroup? Sheesh.]

In article <1180 at fai.UUCP> ronc at fai.fai.com (Ronald O. Christian) writes:
>As I recall, the issue was not the interface between the Exabyte and the
>Symmetry, but that the Exabyte had reliability problems.

When I first saw the 8mm drives, I thought they could be a real godsend for
machines with disk farms. (2 GB on a tape smaller than an audio cassette!) And
for certain environments, they may well be. But the problems I observed were:

- 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....

- The actual transport mechanism is made by Sony, no matter whose name is on
  the box. 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.

- 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. I would not expect an 8mm
  cartridge to hold usable data for more than a year or so. So you'll still
  need something like 9-track for monthly dumps and such.

- Sony has been privately telling potential customers to wait for computer-
  grade DAT drives. These have about half the storage of 8mm, run at about
  the same speed. Supposedly both the media and the drives are more reliable
  than 8mm.

One oddity, too. Pyramid and Sequent aren't selling to PC users; anyone who is
spending >> $100K on a computer is buying something to set in the data center.
It has to look impressive on the balance sheet. And there's this image problem
of telling the Data Center staff that they should be buying blank backup tapes
at K-Mart or Tower Records.... (Sony actually will sell you "data quality"
tapes at about four times the price you can buy them from K-Mart. Same thing,
as far as anyone can tell.)

The natural technology for production use would seem to be the good ol' 1/4"
cartridge. The state-of-the-art here seems to be QIC-150 drives from Cipher,
Tandberg, and others: 150MB on a 600 foot tape. This is essentially the same
amount of storage as a 6250bpi 9-track reel, with comparable recording times.
The interface is usually SCSI or Cipher.

This is a long ways away from 2GB per tape. Given the relatively controlled
nature of the transport in a 1/4" cartridge, you would think that more modern
encoding techniques* would yield incredible amounts of storage, perhaps 10GB,
with high speeds and high reliability. But for some reason no one is willing
to pursue this; they're mucking about with toy tape drives instead.

* If you want to get rich, figure out a cheap way to do helical scan on a 1/4"
cartridge tape.

<csg>