wilson@csli.stanford.edu (Nathan Wilson) (07/11/90)
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@ai.sri.com