SLES 9 and slow 3Ware 8506-12 SATA RAID
 

I received a new server: was delivered with SLES8, upgraded to SLES9.

There is a 3Ware raid controller type 8506-12 installed running 10 SATA 250GB disks.
I formatted the RAID 5 as one big partition (1.9TB).

An identical server is running SLES8 since nearly a year.

Rear/write performance on the old server is lightning fast (up to 55 MB/sec across the network to LTO3), The new server is painfully slow, no more than 5MB/sec in best case with many instances of stalling.

Tech service replace the backplane of one drive set because it was giving drive errors. We expected improvement but no more errors and still painfully slow.

On the new server there is an LTO3 attached to a separate Ultra160 SCSI controller, this is lightning fast when writing data over the network from the older server.

Any suggestions to make this RAID perform normally?

Upgrade the firmware of the card and install the web interface.
There may be an "2TB Auto-Carving" option in the configuration of the web interface. I'm not sure if it's present in PATA, but I know it's present in SATA controllers. Also, for such a large array, I would consider using LVM and partitioning.

There is an auto-verify setting and media error scanning setting that may being running ad infinitum. Enable write cache for that controller. You may want to check out all those options in the web interface as well.

Also, for that number of disks, you will gain speed in a RAID 10 configuration. RAID 5 is fine, but 10 typically beats it out for performance on large drive clusters.

Additionally, consider upgrading the card. The 9500S-12 is intended to be used for what you are doing(enterprise). It has 128MB cache and is benched between 4% and 90% faster than your card due to the redesign. It also has a battery backup(ordered separately) for write cacheing to your array- which is nice if you have a power blip.

Lots of things you can do all in all. I have the same setup on my fileserver, but with 120 GB drives. I wish you luck.

Thoreau,

I found out the hard way that the 3ware 8506 controller really needs the 2.6.9 kernel or above, not present in the SLES 9 version I upgraded to from SLES8. My local Linux guru did 'something' to the older SLES8 server (probably changed to a later kernel) that made it very fast with identical hardware.
So I downgraded my SLES to version 8 SP4 again and will wait for him to come over during the weekend.

SUSE told me that the 2.6.9+ kernel will be in the SLES 9 SP2 that is not out before September.

Novell has just released the open enterprise server.
http://www.novell.com/products/opene...r/oes_faq.html

It uses the 2.6 kernel. I don't know what build number, but if you wanted to check it out, you can get the eval, or you can down it from newgroups for testing.

Maybe it'll be easiest though short-term to have him recompile the kernel until SLES SP2 comes out. Good luck.