Date: Thu, 13 Nov 2003 20:43:28 +0800 From: "nihaopaul" <nihaopaul@hotmail.com> To: "Martin Blapp" <mb@imp.ch>, "Gary Stanley" <gary@outloud.org> Cc: freebsd-scsi@freebsd.org Subject: Re: Very bad FreeBSD SCSI RAID5 write speed performance Message-ID: <BAY2-DAV161Y7PeGbPn00000897@hotmail.com> References: <20031112172306.J4572@pooker.samsco.home> <20031113084355.P13503@cvs.imp.ch> <6.0.0.22.2.20031113062949.028fbea0@localhost>
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what version drives atlas 10k << is that the IV drives? if so what firmware are you running? Paul ----- Original Message ----- From: "Gary Stanley" <gary@outloud.org> To: "Martin Blapp" <mb@imp.ch> Cc: <freebsd-scsi@freebsd.org> Sent: Thursday, November 13, 2003 7:38 PM Subject: Re: Very bad FreeBSD SCSI RAID5 write speed performance > Well. > > W/O softupdates > > root@64:[/tmp/blah]>dd if=/dev/zero of=/tmp/blah/blah > 89472+0 records in > 89471+0 records out > 45809152 bytes transferred in 8.546312 secs (5360108 bytes/sec) > > W/ Softupdates > root@64:[/mnt]>dd if=/dev/zero of=/mnt/blah > 116160+0 records in > 116159+0 records out > 59473408 bytes transferred in 10.080428 secs (5899889 bytes/sec) > > Just about the same. But this machine's write caching settings for the > controller (LSI MegaRaid) are not correct for Raid 5, and the machine's > under some moderate load, so when I get a chance to correct them I'll > repost my findings. I always seem to suffer heavy write speed losses w/ > Raid5, but I can't complain because the read speeds make up for it. > > Also, I use U320 Maxtor Atlas 10K drives, MegaRaid (Latest Firmware, broken > Cache Settings) > > > > > > At 05:33 AM 11/13/2003, you wrote: > > >Hi all, > > > >We are currently testing some raid configurations with Linux > >and FreeBSD. > > > >It seems that FreeBSD does something wrong. An adaptec 3200S > >controller and a IBM ServeRaid5i controller are both times slower > >with RAID5 on FreeBSD as they are on linux. > > > >Both controllers are batterie-backed, have cacheing enabled. > > > >Does anyone with these controllers (drivers) can take some > >numbers of the write-performance ? > > > >If needed I can provide numbers (taken with iozone). I've tested it > >on a async mounted filesystem on both FreeBSD and Linux. And it is not > >only a benchmark problem. We suffer on this problem on production > >machines. The production machines perform a bit better since they > >run 4.X, but still bad (Linux is 3,5 times faster), on CURRENT Linux > >is 4 times faster. > > > >Martin > > > >Martin Blapp, <mb@imp.ch> <mbr@FreeBSD.org> > >------------------------------------------------------------------ > >ImproWare AG, UNIXSP & ISP, Zurlindenstrasse 29, 4133 Pratteln, CH > >Phone: +41 61 826 93 00 Fax: +41 61 826 93 01 > >PGP: <finger -l mbr@freebsd.org> > >PGP Fingerprint: B434 53FC C87C FE7B 0A18 B84C 8686 EF22 D300 551E > >------------------------------------------------------------------ > > > >_______________________________________________ > >freebsd-scsi@freebsd.org mailing list > >http://lists.freebsd.org/mailman/listinfo/freebsd-scsi > >To unsubscribe, send any mail to "freebsd-scsi-unsubscribe@freebsd.org" > > _______________________________________________ > freebsd-scsi@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-scsi > To unsubscribe, send any mail to "freebsd-scsi-unsubscribe@freebsd.org"
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