Ultrium 448 Performance connected to Adaptec SCSI Card 39160

[DMITRESKI]

Hi,

I am not getting the performance out of a newly installed Tape drive. I have an external Ultrium 448 drive connected to an Adaptec SCSI Card 39160 wich is an Ultra160 Controller.

Looking at the doco for the Ultrium 448, I find that it is also an Ultra160 device. The issue I have is that the throughput in Backup Exec 10d is about 250mb/s, where it should be around the 500 to 600 mark.

My question is that if I install an Ultra320 SCSI adaptor, will I get improved performance although the tape drive is only rated at 160.

Thanks & regards
David

[meloni]

The 160 or 320 is only the negotiation speed, ussualy the communication on the scsi channel with only one lto2 is not limited by the negotiated speed (160 VS 320) and I do not think you will solve the problem increasing it.

Usualy the problem is comming from the source of the data.

load L&TT and run the device performance test. this test will create data in the host memory and send it to the lto drive via the scsi bus, this test only involve the processor of the host and the scsi subsystem. you will then know if the problem is comming from the data source as I suspect or fromthe scsi subsystem

[TapeDrive Killer 1 2]

Hi DMITRESKI I dont think changing the HBA will make a difference you need to look the other side of the configuration.
Is your RAID capable of sending 48MB/s ?
Take a look at this PERFORMANCE link

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460

Regards

Pablo Alvarado
Tape Storage DPX

[Etienne GUILLAUMONT]

Hello,

I'm also facing the same problem. There is obviously a problem with the U160 adapter. I changed the adapter to U320 at a customer's and the perf went to normal values (around 4 Gb/min).

A colleague told me that I had to set it to 40Mb/s to improve with LTO tapes :( but I can't find how to do it and I'd like to find a better solution.