Exabyte versus DAT (Summ

[Nathan Wilson]

A while ago I posted asking about the pros and cons of these two mass
storage devices.  Since I received almost as many requests for a summary
as notes containing useful information, I'm posting a summary. From the
responses and my own research I've learned the following:

1) Many more people have Exabyte than DAT.  I did not get a single
   response from someone who actually uses a DAT drive.
2) Exabyte's error checking alogorithm is supposed to be significantly
   better.
3) DAT drives have very fast seek times, but who cares for backups.
4) Exabyte distributors tend to market for only one brand of computer.
   Some of the DAT drives that I've gotten info on work with a truckload of
   different computers, Suns, DEC, HP, IBM, Apple.  As far as I can tell this
   is another uninteresting difference since neither of them should get moved
   around a lot.
5) Exabyte hardware tends to break a fair amount, but at least they tell
   you there is a problem.  From the responses:

   "I've had several of them break: doors jamming, unable to read/write (they
   give you errors, don't worry), the little green light burning out.... I've
   only had about 10 tapes fail so far in the past 18 months [ out of roughly
   900 ].  Most of these tapes got stuck in the tape drives because the
   drives are so cheap."

   "(Our Exabyte) drives have a hard time living on the SCSI bus with other
   peripherals. They seem to hang sometimes, forcing a reboot."

6) Nobody's saying (knows?) anything about the reliability of DAT
   hardware.

The final upshot was that we are getting an Exabyte.

In total, I received 9 responses and 6 requests for a summary.

The responses were from:
Ted Lemon, Gregg Townsend, Tom Slezak, Paul A. Sustman, Art Hays,
Henry Clark, John Richardson, Bill Heiser, and Joe Pruett (hi, Joey :-)

Thanks again!

Nathan Wilson
Teleos Research
nathan%teleos.com at ai.sri.com