Mike Shumko <[log in to unmask]> wrote:
 
>"Paul H. Christidis" <[log in to unmask]> wrote:
>>....
I have used DDS on three HP3000:.
1. One series 958 with one HP-IB-DDS may 91 till now,
       two HP-IB-DDS aug 92 till now
2. One series 920 with one HP-IB-DDS may 91 - dec 92
3. One series 927 with one SCSI-DDS dec 92 till now
 
I backup the 958 6 times a week, and the 92x 5 times a week.
Once a week the backup is total and need two tapes, those tapes
circulate on one year basis. All other days the tapes are reused once
a week. That means that each tape will be used appr. 50 times a year,
and for the period I hav used DDS it sums up to appr 200 backups since
I started. Since dec 92 I always checks the tapes with VSTORE.
If you add those extra runs of tape it sums up to 325 runs for each
tape. Under that time I hav only had one DDS tapes failing. What tapes
am I using? Well five of them are HP 60m DDS tapes running on the 958.
The other five tapes are BASF 60 m DAT tapes (music tapes, not
DDS-tapes) running onthe 92x.
 
My concusion is that you have the same quality with the less expensive
DAT-cassettes as you have with the DDS-cassettes. But with the
lifetimes the tapes have is the cost not critical so why not use the
recommended tapes and HP will stay happy and trust you if the
tape-drives are malfunctioning (they will believe me).
 
Best Regards
Nils-Olov Fransson
Computer dep. Laboratory for Clinical Chemistry
Sahlgrens Hospital, Gothenburg, Sweden.
Phone: +46 10 284 45 25