Symmetrix vs HP local disk (8 x 72gb 15k raid 5), HP winning

[vnad]

I am running some comparisons on a HP ML570 box. We have one 36gb (8GB luns, 0+1) drive on the company EMC Symmetrix attached by two emulex 9802 fibers with powerpath. We also have 400GB drive with 8 x 72gb 15k local attach scsi disks running a raid 5. When I run comparisons, the local attached disk is twice as fast as the SAN. Should this be? Do you think there is some configuration changes we should be making on the Symmetrix or on the HBAs?

 

[Chacalinc]

you must to take a look to the internal symmetrix configuration. The usual problem when metavolumes are created are:

- metavolumes created with no stripes
- metavolumes created with hypervolumes from the same physical disk drive
- not load balanced

Cheers.

 

[vnad]

They are stripped drives and I was told we do not share on the same physical disk. We are also using powerpath software so it is load balanced. Do you mean load balanced on the Sym?

 

[Chacalinc]

yes, you must to take a look to the physical architecture in order to use the best configuration.

Try to ask for a physical map of your volumes (INSIDE the symmetrix).

 

[Chacalinc]

BTW, with load balancing I mean IN the symmetrix, not only ON the symmetrix.

IN = internally.

 

[solarisman]

Find out what the stripe segment size is on the drives on the Symmetrix and make sure that you correlate your volume stripeunit or stripe width to that segment size so that your I/O is is evenly distributed across your disks or raid set (s)

 

[solarisman]

Well, I guess if you are using Windows,,,this is a different story....Wasn't sure what platform...Windows or Unix...