LTO Driver performance

[Curtis Ballard]

Thanks for the posting. The cables and terminator sound OK. Drivers and firmware "up to date" doesn't necessarily mean that they are the same as the ones we have tested here as Adaptec is free to roll both without notifying us. If you can post the revisions you are using we can compare it to what has been used for testing and if it isn't the same we can get those revisions into test.

I have seen a couple of cases where despite having all the right firmware, drivers, and cables, a few HBA's would never negotiation for U320 and it was traced to something specific to that HBA. I think it is possible for an HBA to have a weak transceiver and not be able to operate at U320 speeds with at least some devices.

[Luis Ramírez V.]

Kim:

The problem was resolved because we had another device in the Ultra 320 adaptar, besides the tape backup. Because the 320 that we have is for only one device, we disconnect the other one (a CD-ROM) and the performance now is right.

I hope this could help you.

Best Regards

Luis Ramirez

[Curtis Ballard]

Kim - In your post you indicate that you are using an Adaptec 39160 with an Ultrium 3 drive. That adapter is only a U160 card and will never run anything faster than that but Ultrium 3 drives recommend U320 so L&TT will always give a performance warning. If L&TT is saying that you are running 160 that is the best you are going to be able to do with that card and good enough virtually all of the time with Ultrium 3 but can impact performance on highly compressible data.

[Kim Tørnsø]

Hello Curtis and Lois
I have bee with the customer today, and it shows that they for some time ago have replaced the Adaptec controler. The new controler didn't support multiple LUN, so it seems to bee the reason.
I know that the 39160 only support 160 MB/s, but it is sitting in a DELL server, and that was what DELL recommended for their PCI bus - so thats the reason.(but the L&TT test showed 0,8 Kb/s!)
I'll tell you if the live tests shows if the problem is solved.
Thank you for your replies - it's inspiring with discussions :-)