Performance Problems Compaq DLT 7000 under Win XP

[Alexander Fuchs_2]

Hello dear DLT-experts,

I've got a refurbished Compaq DLT 7000 drive running under windows XP. I'd like to ask two questions about it:

a) Using new tapes and according to the "DLT-sage" utility I've got 2-3 rewrites per GB.

Question: Is that a good figure, or does this mean that the drive is about to fail or something in-between?

b) I can't get the drive to stream decently.

When I backup using backup exec (Veritas) or the Windows utility, I never get more than 3mb/s, even with data that can be compressed very well.

Even if I use the HP storage drive and library tools, I don't get >3mb/s, even though this tool reads the data from RAM,again, no streaming!

I'm not worried about the reduced performance, but the increased tape/drive strain is definitely a concern.

My system: Athlon XP 2500+, nforce2 Chipset, Windows XP, Adaptec 19160, 1x IDE drive @5400 rpm.

Thanks a lot for your replies!

Alexander

[Tina Karasch]

hi Alexander,

pls ensure that the driver you are using to talk to the Dlt is not the "MS driver", But the one from veritas itself - (dlttape-vrts.sys), as the std. MS driver will let you make bu's (as the os applet is the midgit ver. of backup exec), But only very slow ones, as it is using an unchangeable blocksize of 2k instead of a decent one, like the veritas driver 16k or larger, depending on the data on your system
and the setup of it.

here a few performance tuning tips

http://www.hp.com/cgi-bin/cposupport/get_doc.pl?SNI=hpsurestor18545&LC=information_storage&Tfile=lpg50167

http://www.hp.com/cposupport/information_storage/support_doc/lpg50030.html

http://www.hp.com/cposupport/information_storage/support_doc/lpg50032.html

http://www.hp.com/cposupport/information_storage/support_doc/lpg50244.html

http://www.hp.com/cposupport/information_storage/support_doc/lpg50460.html

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50063

also the 19160 is a desktop card that is not the fastest in the world the 29160 is better....

!! correct blocksize setting and system tuning should together with the correct drivers etc should ensure that you get a better result!!

@>'-;---
tk

[Alexander Fuchs_2]

Hi Tina,

thanks a lot for your reply!

Fortunately, the problem has been solved, the tape streams like hell :-)

The Adaptec 19160-driver that came with WinXP was the culprid. It made the tape drive run in "async SCSI" mode which hard-limited throughput to 3mb/s. I got the driver from Adaptec and now everything is ok!

I will go through your performance-related resources, they might be of some use.