[K12OSN] new server serial ATA or SCSI - results on new 3ware card

[Ken Meyer]

Ski --

What SATA drives?

Ken Meyer


----- Original Message -----

From: Chris Kacoroski <ckacoroski at nsd.org>
To: <k12osn at redhat.com>
Sent: Friday, February 27, 2004 4:29 PM

Subject: Re: [K12OSN] new server serial ATA or SCSI - results on new 3ware
card


> Hi,
>
> I got my new system with the following specs:

> - 3ware controller #1 with (2) sata drives in mirrored config as system
> disk

> - 3ware controller #2 with (9) sata drives in raid 5 split into 2 912GB
> partitions (sdb1 & sdb2)

> - Redhat AS3 with all the patches (2.4.21-9.0.1.ELsmp kernel)

> - Dual Xeon 2.4Ghz cpus with hyperthreading so they look like four
> processors
>
> and the results I get with hdparm -tT when run individually are:
>
> /dev/sdb2:

>   Timing buffer-cache reads: 2440 MB in 2.00 seconds = 1220 MB/sec
>   Timing buffered disk reads: 132 MB in 3.01 seconds = 43.85 MB/sec
>
> /dev/sdb1:

>   Timing buffer-cache reads: 2436 MB in 2.00 seconds = 1218 MB/sec
>   Timing buffered disk reads: 132 MB in 3.03 seconds = 43.56 MB/sec
>
> /dev/vg00/lvRoot:

>   Timing buffer-cache reads: 2228 MB in 2.00 seconds = 1214 MB/sec
>   Timing buffered disk reads: 110 MB in 3.03 seconds = 36.30 MB/sec
>
> when I run them at the same time, the results drop to:
>
> /dev/sdb2:

>   Timing buffer-cache reads: 1760 MB in 2.00 seconds = 880 MB/sec
>   Timing buffered disk reads: 102 MB in 3.14 seconds = 31.19 MB/sec
>
> /dev/sdb1:

>   Timing buffer-cache reads: 1780 MB in 2.00 seconds = 890 MB/sec
>   Timing buffered disk reads: 98 MB in 3.03 seconds = 32.34 MB/sec
>
> /dev/vg00/lvRoot:
>   Timing buffer-cache reads: 1200 MB in 2.00 seconds = 600 MB/sec
>   Timing buffered disk reads: 108 MB in 3.00 seconds = 36.00 MB/sec
>
> To me the interesting thing is that the system partition also slows
> down even though it is on a separate 3ware card.  I plan to do some
> more extensive testing next week, but initially it looks like it will
> keep up with a scsi based system.
>
> --
> "When we try to pick out anything by itself, we find it
>    connected to the entire universe" John Muir
>
> Chris "Ski" Kacoroski, ckacoroski at nsd.org, 425-489-6263