topic VA7400 optimum performance in Disk Enclosures

VA7400 optimum performance

kirit_2 — Tue, 06 Jul 2004 02:41:36 GMT

I would like to know about what should be the usage capacity of VA7400 for optimum performance.

For my case we have one main enclosure ( 15 disks 0f 73 GB ) and one JBOD ( 5 disks of 73 GB).

VA7400 with dual controller and 512 MB RAM.

raid level is AUTORAID.

Re: VA7400 optimum performance

Peter Mattei — Wed, 07 Jul 2004 01:53:36 GMT

You will get best performance in RAID01 mode or if occupancy in AUTORAID mode is low enough to store all data in RAID01.
In your case this is round 600GB allocated to LUNs.

To find out more about performance behavior of the VA7400 I suggest you have a look at the user guide (Product features)
http://h200005.www2.hp.com/bc/docs/support/SupportManual/c00088801/c00088801.pdf
and the attached performance whitepaper.

Cheers
Peter

Re: VA7400 optimum performance

kirit_2 — Wed, 07 Jul 2004 02:36:29 GMT

Hi,

Thanks for your reply.

I attach some more data of VA7400, if you can look into this special case and advice.

Re: VA7400 optimum performance

Peter Mattei — Wed, 07 Jul 2004 02:43:22 GMT

Sorry, I can not open your attachment "122468.null"!
Peter

Re: VA7400 optimum performance

Uwe Zessin — Wed, 07 Jul 2004 02:50:04 GMT

Peter,
it is a simple text file. You can save it to a local disk first.

Re: VA7400 optimum performance

kirit_2 — Wed, 07 Jul 2004 02:54:38 GMT

Hi,

Please find attachment again.

Re: VA7400 optimum performance

Peter Mattei — Wed, 07 Jul 2004 03:11:20 GMT

Well, you have allocated almost all available capacity in AUTORAID mode.
This means that a major part of your data has to be stored in RAID5DP which is not bad, but will affect performance when doing lots of small random writes.
In a read dominant environment or when you are writing large junks RAID5DP performs well.

If you want to improve the RAID01 / RAID5DP ratio, just add some more disks. The VA7400 will then migrate data to RAID01.

To find out the real RAID5DP allocation of your VA use Command View go to the performance tab, modify your view: select RAID1 and RAID5DP allocation option.
This will show the ratio.

Cheers
Peter

Re: VA7400 optimum performance

Ted Buis — Thu, 08 Jul 2004 17:16:31 GMT

There are many ways to tune HP-UX I/O performance such as scsi queue depth, buffer cache size (larger not always better) and mount options, so don't just concentrate on the array.