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LSi MeraRAID performance problem

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Hi all,

We try to start high load server with this config:

Tyan S2891

2xOpteron 252 Proc.

4 GB RAM

LSI MegaRAID 320 2X

6 x 146 Seagate 10k. SCSI HDD

After array creatation we do not found the expected performance.

It is RAID 5 config and we are able to get only ~65 MB/sec on read.

We posted the problem to LSI Logic without any answer and recomendation.

As OS we tried FreeBSD 5.4, Linux Redhar AS 3.0 and Windows 2003 Server with the same result.

Exists some one using similar configuration and if yes pls. tell us about the read performance.

Also exists some one using LSI MegaRAID 320 2x ot tyan S2891 ?

many thanks in advance,

ivan.

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Hi all,

We try to start high load server with this config:

Tyan S2891

2xOpteron 252 Proc.

4 GB RAM

LSI MegaRAID 320 2X

6 x 146 Seagate 10k. SCSI HDD

After array creatation we do not found the expected performance.

It is RAID 5 config and we are able to get only ~65 MB/sec on read.

We posted the problem to LSI Logic without any answer and recomendation.

As OS we tried FreeBSD 5.4, Linux Redhar AS 3.0 and Windows 2003 Server with the same result.

Exists some one using similar configuration and if yes pls. tell us about the read performance.

Also exists some one using LSI MegaRAID 320 2x ot tyan S2891 ?

many thanks in advance,

ivan.

213000[/snapback]

How did you configure the cache? What are you using to benchmark it with windows? Are all the drives in the array or are some spares etc?

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Hi,

thanks for the answer!

>How did you configure the cache? What are you using to benchmark it with windows? Are all the drives in the array or are some spares etc?

The RAID is with 128 MB Chache, configured with readback and writeback.

All the disks are into array.

We are using Windows 2003 server and tested with HD Tach version 3.0.1.0 (www.simplisoftware.com).

On FreeBSD and linux we are using dd and iostat.

regards,

ivan.

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I don't know if current HDTach versions have changed, but older versions were no good for benchmarking many RAID configurations due to the specific method it used for reading. The Disk Transfer Rate test of Winbench99 is much more reliable for testing sustained transfer rates.

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One immediately obvious problem is that the S2891 does NOT sport a 133 MHz PCI-X slot, even though the MegaRAID card supports 133 MHz PCI-X. :blink::o:(

Instead, it only offers 100 MHz, so even though the slot is apparently physically and software compatible, you will be losing 33% of your potential bandwidth before you even start to take into account other overhead and possible limits imposed by only have 128 MB of cache.

Edited by Trinary

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Unless there is a serious compatibility issue with the Tyan board I do not see how that could be a problem. Even a 100Mhz PCI-X slot should provide bunches more bandwidth than those drives in RAID can ever deliver.

I have a Megaraid 300-8x SATAII controller and at first I had somewhat of the same problems. but tweaking some of the controller options, and trying out different stripe sizes for the array in combination with different cluster sizes for the filesystem did eventually give me acceptable results. But also only with decent benchmarking software like IOMeter, other more common benches seem to choke on the array...

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Thanks for the answers,

As the beginning I need info about wath to expect from this RAID.

If some one have data about the SCSI RAID performance pls. send it.

I need the best possible read performance.

If needet I will change the MB or the RAID .

Pls. suggest some good RAID vendor.

We are not looking for low cost solution.

And any test results ( for compare) will be great.

ragards,

ivan.

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