Date: Thu, 16 Dec 1999 11:48:38 -0500 (EST) From: David Gilbert <dgilbert@velocet.ca> To: Brad Knowles <brad@shub-internet.org> Cc: David Gilbert <dgilbert@velocet.ca>, freebsd-current@FreeBSD.ORG Subject: Re: AMI MegaRAID datapoint. Message-ID: <14425.6118.899093.621159@trooper.velocet.net> In-Reply-To: <v0422081ab47ebe7ceb22@[195.238.1.121]> References: <14425.2778.943367.365945@trooper.velocet.net> <v0422081ab47ebe7ceb22@[195.238.1.121]>
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>>>>> "Brad" == Brad Knowles <brad@shub-internet.org> writes:
>> This is impressive and subject to the bug that I mentioned in
>> -STABLE which still hasn't been found.
Brad> Which one is this?
It's a really long thread. I'm not going to repeat it here.
Basically, under "enough" load, vinum trashes the kernel stack in such
a way that debugging is very tough. I have been talking to a number
of people about it in -STABLE. I will continue to debug this on the
new news server I'm building (before it gets commissioned), but work
on this particular server had to halt with the instalation of the
MegaRAID.
Brad> With luck, in about a month or so, I should be getting a new
Brad> server in with 1GB RAM, 450Mhz Pentium III w/ 1MB L2 cache, a
Brad> DPT SmartRAID V controller with 256MB ECC cache, and eight
Brad> Fujitsu MAE3182LC 7200RPM 18GB drives for RAID-5 configuration
Brad> on a single SCSI bus, for our new anonymous ftp server.
I got the MegaRAID 1400 because the DPT V drivers weren't available.
The MegaRAID should be roughly equivlanet to the DPT V. Do go with
LVD if you can.
I have done benchmarking with bonnie instead of rawIO. The output is
as follows:
1 process, for vinum:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
raid-1 512 4554 20.0 4583 6.3 4495 8.3 18596 80.1 30001 25.9 446.0 5.3
1 process, for MegaRAID:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
mega 512 7419 32.4 7529 10.2 4653 9.6 14616 63.4 14942 18.8 345.4 5.0
... now the MegaRAID was at 16.5M/s block read with a different stripe
size, but I don't have that output in front of me.
Dave.
--
============================================================================
|David Gilbert, Velocet Communications. | Two things can only be |
|Mail: dgilbert@velocet.net | equal if and only if they |
|http://www.velocet.net/~dgilbert | are precisely opposite. |
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