Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.access.net.au!news.netspace.net.au!news.mel.aone.net.au!grumpy.fl.net.au!news.webspan.net!newsfeeds.sol.net!hammer.uoregon.edu!news.mathworks.com!EU.net!Ireland.EU.net!maths.tcd.ie!maths.tcd.ie!not-for-mail From: ajudge@maths.tcd.ie (Alan Judge) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: FreeBSD 2.1.6 Striping Performance Date: 5 Feb 1997 10:28:39 -0000 Organization: Dept. of Maths, Trinity College, Dublin, Ireland. Lines: 35 Sender: mathnews@gosset.maths.tcd.ie Message-ID: <5d9ncn$hv@gosset.maths.tcd.ie> References: <5d87kv$sin@news.pcslink.com> NNTP-Posting-Host: gosset.maths.tcd.ie Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:35039 ryan@pcslink.com (Ryan Mooney) writes: >I was just playing with striping under 2.1.6 and I got fairly poor performance >results... You don't say what results you actually got, but I've a few suggestions anyway. First of all, a 10M test file is way too small to get realistic numbers. You're more likely to measure the performance of your memory system. Also, I'd try a larger interleave. I doubt that the problem is related to the version of FreeBSD or of the ahc driver, but I'll leave better informed people to address that. However, I can provide some numbers for a 2.2-BETA system. Hardware: PPro 180 (128M RAM, PCUI) System disk on internal SCSI Adaptec 2940UW with 3 Quantum Atlas II 4GB UltraSCSI Striping: Full 4GB partition on each drive, interleave as below. Performance tested with iozone (2GB file, 64K reads and writes) Interleave Read perf Write perf 16 21MB/s 11MB/s 32 23.9 15.2 64 24.5 18.8 128 24 18.7 256 21.5 19.9 512 20 20 2048 11.7 20 You'll note that there is a slight trade off between read and write speed. All of this is sequential of course. Your application might vary. -- Alan Judge Like punning, programming is a play on words. -- Alan Perlis