Ultrium 2/20 Library slow when connected to 2 HBAs

[Jose Ros]

I have performance issues with the Ultrium 2/20 library when connected to a host with 2 HBA's.

Here's what I've got:
* LT 6000r with 2 HBAs
* VA 7400
* Ultrium 2/20 library
* Brocade SilkWorm 2800
* Veritas BackupExec 8.6
* Windows 2000 Adv Server (SP2)
* Fiber Channel driver version 3.0.4107.0.

When I run a backup operation with both HBA's connected, I only get about 21 GB/hour.

If I disconnect one HBA, I get around 106 GB/hour which is close to the Ultrium's advertised 30Mbps transfer rate.

Please advise.

[Marino Meloni_1]

hy,
are you running the two hba togheter or one at a time?, you may have performance problem if you cannot supply the ultrium with a continus flow of data, you can use a tools called PAT from hp site to check the performance of your server with the two adapter.
the issue can be caused by the source of the data which are caollected, or aslso by the fact that the hba are put togheser on the same pci bus, may be over a pci-bridge.
bye
marino

[Eric de Lange_2 · Accepted solution]

Jose,

When the 2 HBA's are connected, Windows will see all hardware 2 times, once via HBA1 and once via HBA2. Because Windows claims all harwdare that it sees on it's busses you will need a 'filter' driver to regulate this. I am not sure if you have a filter driver installed but if not try the following:

Create a port-zone (on the brocade) tying one HBA to the tape/library ports and the other HBA in the server dedicated for VA7400 access. If this speeds up your performance, it may be just that Windows was confused.

If this does not resolve the issue, you may want to check the following: Netservers usually have a peer bus structure. If all storage adapters (including the HBA's) are on one peer bus it might be that the PCI bus they are plugged into is overloaded. In that case, it might be good to distribute the storage adapters in the server such that bot HBA's are on a different peer bus.

Also make sure your Netserver has the latest BIOS versions and such.

Hope this helps !

-Cal.

[Jose Ros]

UPDATE: I've created two zones on the Brocade and moved the HBA's to separate PCI busses. However the problem still persists- tape backup is extremely slow when both HBA's are connected.

Any more suggestions would be greatly appreciated.

Thanks.

[Eric de Lange_2]

Hi Jose,

OK, time to get into details. This may sting a bit :-)

You have now made a disc zone exclusive to the VA7400 and a tape zone for the 2/20 Ultrium lib. So internally to Windows there should be no confusion about what data needs to go where. Yet, backups are extremely slow (comparatively speaking). This brings up the question: Is disc access equally slow when 2 HBA's in the machine ? Maybe this needs to be measured ?

A tool that you can use to test this is the Performance Assessment Tool off the HP website. This will measure the file system speed (in this case the filesystem on the VA7400) and indicate if there is an equal performance drop or not.

Personally I think that the issue is between the Netserver, the OS and the FC driver but I will do some checks over the next few days.

best regards,

-Cal.

[Simon White]

Jose,

I have had similar performance issues when running with 2 HBAs and would be very interested in any answers. My situation was slightly different in that I had:
* LXr8500 with 2 HBAs
* VA7100 - fully populated with 15 disks
* Windows 2000 Advanced server (SP2)
* HP Autopath
* Fiber driver 3.0.4107.0
The application I was benchmarking was extremely IO intensive, so I was expecting that with the dual HBAs and the high performing VA7100 I would receive excellent IO rates - unfortunately this wasn't the case. I received the same rate (or sometimes worse) if I connected up the VA to both HBAs compared to the rate I got if I connected just one HBA . HP's Autopath software seemed to work for redundancy for not quite so well for load-balancing. I was using a product called ioscan to measure the performance and didn't really come close to the 90MB/s figure published by HP. I also tried to split the HBAs across 2 PCI buses but this didn't have any affect.
When I ran the same test using a HP-UX server the results were closer to the 90MB/s and both HBA cards were being utilised.

Simon