MSL 5030 performance problems

[Michael Kunze]

I have a MSL 5030 LTO1 Library connected to a DL360G3 Server (dual channel U320 Controller). I'm using Backupexec 9.0 with the latest Hotfixes under Windows 2000. With an older system and DLT-Library in the same environment I had a data through-put from about 2,5MB/s. Now, with the new comonents, my data through-put is only about 170KB/s (!). Any idea what I can do? I've got the information to disable the mediachanger service under Windows 2000, but this had no effect on the backup speed...

[Marino Meloni_1]

hi
For sure you have a problem, have a look in those documents, there is a lot of info and some tools that could help you in testing differents components

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50049

http://h20015.www2.hp.com/en/document.jhtml?lc=en&docName=lpg50460

[Jan Klier]

The LTO1 drive is a higher performance drive than the DLT. And most tape drives have to be fed data at a minimum speed so they can stream the data (meaning the data come fast enough that it doesn't have to pause tape movement to wait for additional data). LTO1 drives acutally have advanced technology that can adjust the speed of tape movement to match the speed at which data come in to accomodate a wider range of configurations. But the bottom end of this scale is 6MB/s - below that, the drive starts starting and stopping and you will see a dramatic drop in performance. You stated you had 2.5MB/s with the DLT. If that rate is a function of your system and bus rather than the drive, then this would be the reason for the LTOs behavior.

There are performance tools available from the HP web site to both test your system and drive performance to help out with this kind of problem.

[Curtis Ballard]

That transfer rate sounds very much like you might have a SCSI negotiation problem. Make certain that you are using the latest version of the driver for your controller as there was a version that had trouble with LTO drives. You can check the negotiated transfer rate via Insight Manager or you can run HP StorageWorks Library and Tape Tools then pull a support ticket and look in the "Device Details" for the drives.

I won't provide detailed instructions for either here since they are documented so many times in other places. If you need a link or documentation post a request in this thread and I'll dig up a link to the documentation.