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LTO Driver performance

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Luis Ramírez V.
Occasional Advisor

LTO Driver performance

We have an LTO Ultrium-1 215 internal installed in a Proliant ML570 G1. The tape is attached to a Ultra320 HBA, but when I check the tape using the L&TT health, it says the following:

"The current SCSI configuration is likely to be limiting the performance of the drive.
Please check that your HBA is the correct type for the drive and that the cabling is good.
The SCSI configuration referenced is the one for which device analysis was run and/or the support ticket was pulled.
If this is not via your backup server then you may not have an issue.
Current SCSI transfer rate limited to: 20 MB/sec. Recommended: 80 MB/sec. or better
The drives hardware compression algorithm is currently switched off.
This was probably set by the backup software.
The drive's setup has not been altered."

We used the NTBackup utility, but our plans are change it. I don't know if this problems are because the NTBackup or any parameter in the HBA.

Maybe somebody can give me a light about a way to try to increase the tape performance.

Thanks for all your help.

Luis Ramírez V.
13 REPLIES
Marek Nelec
Honored Contributor
Solution

Re: LTO Driver performance

Check if your SCSI cable is properly terminated. You should use 68-pin SCSI cable terminated with LVD/SE terminator. If your terminator simply reads "SCSI", not "LVD/SE", that would be the problem.
Luis Ramírez V.
Occasional Advisor

Re: LTO Driver performance

I'll check the HBA cable. The 215 is internal and I installed a different tape backup, a external Ultrium3 920 and the behavior was the same. Maybe the internal cable affects the external tape?

Thanks again for all your help.
Luis Ramírez V.
Occasional Advisor

Re: LTO Driver performance

The cable that I used to connect the external tape is C2362B, that, according to HP, is SCSI LVD. Is it right for the tape?
Marek Nelec
Honored Contributor

Re: LTO Driver performance

Luis, if you are using dual channel SCSI HBA, then you can have internal and external drive connected to the same HBA, but to two different channels. If your SCSI HBA is a single channel , but with internal and external connectors, then you should connect devices _EITHER_ to the external _OR_ to the internal connector. The cable that you mention is 68-pin VHDCI to 68-pin HD D-sub EXTERNAL cable. It's compatible with LVD devices, but the device should still be terminated with LVD terminator, regardless if it is an external or internal device. So if you have both internal and external drive connected to the same HBA disconnect one of them, check the terminator and then check if L&TT still says something about limited performance of the SCSI channel.
Luis Ramírez V.
Occasional Advisor

Re: LTO Driver performance

Thanks for all your help. I'll check for the terminator and try to disconnect the internal tape and using only the external.
wol_1
Occasional Visitor

Re: LTO Driver performance

Hi,

I have very similar problem. Ultrium-3 1/8 Autoloader is the only device connected to Ultra320 HBA (Adaptec 39320A none raid). It is connected and terminated with factory cable and terminator supplied by HP common with device. The HBA is configured correctly, firmware and drivers are updated to latest for HBA and Autoloader. The autoloader device works fine but L&TT says the speed is limited to Ultra160.

Regards
Kim Tørnsø
Occasional Visitor

Re: LTO Driver performance

Hey
I too, have a similar problem with Ultrium 3-SCSI in a MSL TapeLibrary. Connected to Adaptech 39160 (no other devices connected). All firmware and drives are updated.
L&TT reports the same warnings.
Have you got a solution by now?
Curtis Ballard
Honored Contributor

Re: LTO Driver performance

I see several posts here for speed negotiation issues. I don't know what the cause of the issues is, typically it is an HBA firmware issue, driver issue, or cabling issue.

I would try a few different driver revisions and check to see if there are different revisions of firmware for the HBA if there aren't any obvious cabling issues. Feel free to post if you find something that works. If it is an HBA driver or tape drive we can go back to the vendor and ask them to fix it.

Regardless of the cause, an LTO Ultrium 1,2, or 3 drive running at U160 will perform at it's maximum rate in most environments so I wouldn't be too concerned about U160 with those drives.
Kim Tørnsø
Occasional Visitor

Re: LTO Driver performance

Hello Curtis
Here are some more informations:
The SCSI cable is delivred with the the Library - compaq spare: 110941-001.
The terminator is MSKL R800-01A Ultra320 LVD/SE.
To me it seems that both cable and terminator are OK!
The driver and firmware for the Adaptec 39160 are up to date.
To me it seem more and more like a combatibility issue between Adaptec and HP!
Curtis Ballard
Honored Contributor

Re: LTO Driver performance

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.
Occasional Advisor

Re: LTO Driver performance

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
Honored Contributor

Re: LTO Driver performance

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
Occasional Visitor

Re: LTO Driver performance

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 :-)