topic Re: Does configuring more than one LUN improve performance using HPUX and a va7400 in Disk Enclosures

Does configuring more than one LUN improve performance using HPUX and a va7400

Bill Costigan — Thu, 21 Mar 2002 14:57:55 GMT

I'm trying to understand where the bottlenecks are along the data path from an HPUX system and the VA7400 and how the VA queues and handles IO requests from multiple LUNs

If we start with a single volume group containing one LUN could get get more throughput by:

1. adding a second LUN to the volume group if the second LUN is in the same redundancy group.
2. adding a second LUN to the volume group if the second LUN is in the other redundancy group.

If one system was requesting IO across 4 LUNs and a second system was using only 1 LUN would the first system see better performance

Re: Does configuring more than one LUN improve performance using HPUX and a va7400

David Bell_1 — Thu, 21 Mar 2002 15:54:45 GMT

Bill,

There are several factors to consider here. However, generally speaking, the (4)LUN configuration would see better performance if configured correctly. My configuration method would be to configure (2)LUNS in separate Raid Groups, put them both in the same Volume Group, then stripe across the controllers. In other words, when viewing the vgdisplay, you will see alternate paths for each disk. Utilize the vgreduce/vgextend commands and reduce/extend the alternate paths to where you're utilizing BOTH paths simultaneously.

All the best,

Dave

Re: Does configuring more than one LUN improve performance using HPUX and a va7400

David Bell_1 — Thu, 21 Mar 2002 16:09:27 GMT

Bill,

You may also want to look at the following:

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=b5c92172183287ea25/screen=ckiDisplayDocument?docId=200000058164219

If you can't get to the URL, the document ID is lpg35000.

Dave

Re: Does configuring more than one LUN improve performance using HPUX and a va7400

Bill Costigan — Thu, 21 Mar 2002 19:30:43 GMT

David,

Thanks for the info.

I cannot find doc lpg35000.

Any clue where it might be?

Re: Does configuring more than one LUN improve performance using HPUX and a va7400

David Bell_1 — Thu, 21 Mar 2002 19:59:40 GMT

Bill,

Oddly enough the link is no longer valid. I did find a similar document on LUNS at:

http://www.hp.com/cposupport/information_storage/support_doc/lpg35039.html

You may also want to look here for manuals, faqs, etc.

http://www.hp.com/cposupport/manindex/hpsurestor43759_eng_man.html

As well as this one:

http://www.hp.com/products1/storage/disk_arrays/midrange/va7400/infolibrary/index.html

I personally like the last one for the in depth information on virtualization, etc. Wait, I feel my propeller beginning to turn...

HTH,

Dave

Re: Does configuring more than one LUN improve performance using HPUX and a va7400

Bill Costigan — Thu, 21 Mar 2002 20:24:47 GMT

Thanks Dave,

Now I have some good bed time reading. :-)

Bill