topic Re: DLT Thoughput in Operating System - HP-UX

DLT Thoughput

Jon Mattatall — Wed, 19 Dec 2001 20:35:25 GMT

Hi all...
Silly, stupid question, but...
If the tape librarian puts a DLT II tape in the tape drive when we usually use a DLT III, would the]
throughput decrease accordingly? I've got a server that normally requires ~50min. to complete daily backup (full) but now and then requires ~2hrs.

Logs look identical for both cases, no hung processes, no waits before stopping Oracle, etc.

Am I reaching?

Dazed, confused, and grasping at straws
Jon

Re: DLT Thoughput

Patrick Wallek — Wed, 19 Dec 2001 20:47:38 GMT

Anything is possible.

Are you talking about DLT or DDS? Most current DLT tapes are DLTIV and will work in a DLT[4,7,8]000 drive.

There are differences between DDS 2 and DDS 3 tapes, but I don't know if speed is necessarily one of those differences. Capacity definitely would be with DDS2 at 120 meters and DDS3 at 125 meters.

Re: DLT Thoughput

Sanjay_6 — Wed, 19 Dec 2001 20:50:10 GMT

Hi Jon,

don't think there should be such a big difference in time while backing up the same amount of data. The throughput is dependent on the model of the drive and not the medium. your problem could be that the media which required 2 hrs to back up something normally backed up in 50 minutes should be replaced. It could be having bad patches on the medium and the drive is trying to recover from the bad media which delays the overall backup time.

Hope this helps.

Regds

Re: DLT Thoughput

Helen French — Wed, 19 Dec 2001 21:00:49 GMT

Hi Jon,

Normally the throughput depends on the Tape drive rather than the media.

See this links:
http://us-support2.external.hp.com/cki/bin/doc.pl/sid=4bffeb7f1c793a3eb3/screen=ckiDisplayDocument?docId=200000057220122

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=4bffeb7f1c793a3eb3/screen=ckiDisplayDocument?docId=200000057218874

shiju