[CentOS] Centos 3.4 3ware 9500S Floppy Boot Disk

Wed Apr 27 00:23:27 UTC 2005
Joshua Baker-LePain <jlb17 at duke.edu>

On Tue, 26 Apr 2005 at 3:05pm, Seth Bardash wrote

> Centos 4.0 has the driver built in.
> We recommend you install 4.0 and then build the latest (9.2) driver and
> firmware from source (you must set up your kernel source tree to match the
> running kernel). 
> Build it with the firmware in the driver so that at the next boot it will
> upgrade the firmware. See 3ware's web site on how to do this. We will be
> adding a page that describes this in detail in the future.
> Once built, you need to copy it to the appropriate
> /lib/modules/kernel_version/kernel/drivers/scsi directory.
> Then run mkinitrd to create a new initrd image. Name it something else that
> is NOT the default. 
> edit grub.conf and add a copy of the existing boot entry but change the
> initrd image entry to match the new image created above. 
> Reboot and test it to make sure it works fine. If it does then save the old
> image as file.old and name the new one the same name as the original old
> one. Then delete the grub.conf entry you made for testing and you will be
> good to go.
> After you have all this running then install the latest version of 3dm2 from
> 3ware's site.

All good advice, except for the fact that upgrading my daul 9500-12 system 
from the codebase/stock centos-4 driver to the 9.2 codebase 
(including driver) utterly killed the performance.  The 9500s are set up 
as RAID5 w/ a hot spare, and I do a software RAID0 stripe across them.
These are tiobench numbers before "upgrading" (units are MB/s):

Read, 1 thread: 428.8
Read, 2 thread: 586.7
Read, 4 thread: 541.5
Read, 8 thread: 462.9

Write, 1 thread: 151.7
Write, 2 thread: 156.8
Write, 4 thread: 148.6
Write, 8 thread: 148.5

And after:

Read, 1 thread: 433.4
Read, 2 thread: 608.1
Read, 4 thread: 508.6
Read, 8 thread: 398.6

Write, 1 thread: 33.7
Write, 2 thread: 31.6
Write, 4 thread: 31.4
Write, 8 thread: 30.5

The bonnie++ results look even worse:

"Old" codeset:
Read:  340.6
Write: 173.5

"New" codeset:
Read: 134.5
Write: 35.6

I've got a request into 3ware for support, but no response yet.

Joshua Baker-LePain
Department of Biomedical Engineering
Duke University