Date: Thu, 16 Dec 1999 17:35:28 +0100 From: Brad Knowles <brad@shub-internet.org> To: David Gilbert <dgilbert@velocet.ca>, freebsd-current@FreeBSD.ORG Subject: Re: AMI MegaRAID datapoint. Message-ID: <v0422081ab47ebe7ceb22@[195.238.1.121]> In-Reply-To: <14425.2778.943367.365945@trooper.velocet.net> References: <14425.2778.943367.365945@trooper.velocet.net>
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At 10:52 AM -0500 1999/12/16, David Gilbert wrote: > Now... using vinum and either the 2940U2W (Adaptec LVD) or the TekRAM > (NCR) LVD (using the sym0 device) gives 30 to 35 M/s under RAID-5. That's really interesting, because there are at least two or three outstanding bugs in the vinum RAID-5 implementation that have prevented me from successfully benchmarking it (see <http://www.lemis.com/vinum/bugs.html>). Have you been using rawio? Have you made any attempt to try duplicating some of the sorts of benchmarks I've done, available at <http://www.shub-internet.org/brad/FreeBSD/vinum.html>? > This is impressive and subject to the bug that I mentioned in -STABLE > which still hasn't been found. Which one is this? > The AMI MegaRAID 1400 delivers between 16.5 and 19 M/s (the 19M/s > value is somewhat contrived --- using 8 bonnies in parrallel and then > summing their results --- which is not 100% valid)... but the MegaRAID > appears to be stable. If you look at the page I mentioned, you'll see that my best sustained speed with a vinum 4-way stripe on IBM 10kRPM 9LZX drives attached to an Adaptec 2940UW controller was about 19MB/s sequential read (anywhere from four to 128 processes), 16.5MB/s random read (64-256 processes), 14MB/s sequential write (16 processes), and 15MB/s random write (64-256 processes). My best performance with a DPT SmartRAID IV in a 4-way stripe with the same disks was 16.5MB/s sequential read (4 processes), 7.5MB/s random read (pretty much regardless of how many processes), 17MB/s sequential write (256 processes), and 6MB/s (independent of the number of processes). I did not attempt to benchmark DPT SmartRAID IV performance under RAID-5. I'd be very interested to see more extensive benchmarking of this configuration. In addition to my page above, I'd recommend you look at <http://www.acnc.com/benchmarks.html>; and <http://devlinux.com/projects/reiserfs/bens.html>, and see which of these you can throw at your system. With luck, in about a month or so, I should be getting a new server in with 1GB RAM, 450Mhz Pentium III w/ 1MB L2 cache, a DPT SmartRAID V controller with 256MB ECC cache, and eight Fujitsu MAE3182LC 7200RPM 18GB drives for RAID-5 configuration on a single SCSI bus, for our new anonymous ftp server. I know this isn't an ideal configuration (I shouldn't have more than four devices on a SCSI bus, and I should be using faster drives with lower latency), but it will be very interesting to test out this configuration with 3.4-RELEASE and what should hopefully be stable DPT SmartRAID V/VI drivers by then. I plan on beating the crap out of this machine before it goes online. ;-) -- Brad Knowles <brad@shub-internet.org> <http://www.shub-internet.org/brad/>; <http://wwwkeys.pgp.net:11371/pks/lookup?op=get&search=0xE38CCEF1>; Your mouse has moved. Windows NT must be restarted for the change to take effect. Reboot now? [ OK ] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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