Re: Disk performance problem

[Olaf Reitmaier Veracierta <olafrv@gmail.com>]

On 25/02/10 05:18, Veli Cakmak wrote:

Dear Friends;

I have servers which contain SATA disks and SAS disks. I was testing the speed of writing on these servers and I recognized that SAS 10.000 disks much more slowly than the SATA 7200. What do you think about this slowness? What are the reasons of this slowness?

Does your server match this setup:

- SATA and SAS disk are connected on different RAID controllers.
- Both RAID controllers have enabled disk read and disk write caches.
- SATA disk are in a hw RAID 5 or 6, and one logical drive A.
- SATA disk are in a hw RAID 5 or 6, and one logical drive B.
- Drive A is configured with LVM 1.
- Drive B is configured with LVM 2.
- Partition on LVM1 and LVM2 are in the same filesystem format (i.e. ext3, reiserfs, xfs).
- Having a multicore CPU.

If not slowness can be caused by not configuring some items before.

Try using bonnie++ and stress to test your disks.

 

Thank you for your help.

It's ok.

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