From owner-freebsd-hackers Thu Feb 8 4:50:41 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from gandalf.vi.bravenet.com (gandalf.bravenet.com [139.142.105.50]) by hub.freebsd.org (Postfix) with SMTP id E75D537B491 for ; Thu, 8 Feb 2001 04:50:22 -0800 (PST) Received: (qmail 15557 invoked by uid 1000); 8 Feb 2001 12:49:52 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 8 Feb 2001 12:49:52 -0000 Date: Thu, 8 Feb 2001 04:49:52 -0800 (PST) From: Dan Phoenix To: Geoff Buckingham Cc: Julian Elischer , Matt Dillon , Andrew Reilly , Alfred Perlstein , Andre Oppermann , Rik van Riel , Mike Silbersack , Poul-Henning Kamp , Charles Randall , Jos Backus , freebsd-hackers@FreeBSD.ORG Subject: Re: vinum and qmail (RE: qmail IO problems) In-Reply-To: <20010208120831.C61928@chuggalug.clues.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG negative on that houston :) http://www.FreeBSD.org/cgi/getmsg.cgi?fetch=52705+54899+/usr/local/www/db/text/2000/freebsd-scsi/20001008.freebsd-scsi ..i think maybe thread you are talking about. Not to much info I could find on specifically on what you are talking about. ...but again are you talking about venim or ccd? I'll keep cluster solution in mind for the 2 disks. On Thu, 8 Feb 2001, Geoff Buckingham wrote: > Date: Thu, 8 Feb 2001 12:08:31 +0000 > From: Geoff Buckingham > To: Dan Phoenix > Cc: Julian Elischer , > Matt Dillon , > Andrew Reilly , > Alfred Perlstein , > Andre Oppermann , > Rik van Riel , Mike Silbersack , > Poul-Henning Kamp , > Charles Randall , Jos Backus , > freebsd-hackers@FreeBSD.ORG > Subject: Re: vinum and qmail (RE: qmail IO problems) > > On Thu, Feb 08, 2001 at 03:41:59AM -0800, Dan Phoenix wrote: > > > > > > > > Yes I did and it made some real differences. I enabled it on /usr as well > > as /var and mounted /var with the noatime option. Doing not bad for the > > amount of email it is pushing....thing is this I/O problem never use to be > > an issue....but with growth constantly happening it has come to a hardware > > based solution. What I have recommended to the company is a scsi card in > > that machine with 2 scsi drives.....I will raid 0 then together with ccd > > or venim and mount it as /var....turn existing /var into extra swap > > space.....although i may thing of something else...as I don;t think it > > needs a gig of swap... and that should fix the I/O issue incredibly. > > Right now I have split up the load also between2 machines so that has > > helped out incredibly....but systat -vmstat is still always showing 100% > > disk usage so I will have to remedy the problem. Then I plan on moving all > > mail back to that one machine and beating the shit right out of that > > freebsd machine to see what freebsd can really handle. If anyone has some > > nice newbie docs :) on ccd or venim would be greatly appreciated. > > > > > A word of warning on this, when striping on an even number of drives > using a power of 2 as as the stripe size, it is very easy to concentrate > meta data on one drive, thereby doing away with much of your performance gain. > > Workarounds include striping at cluster size (16 or 32MB usually) using and > odd number of disks (for non raid 3/5), though or experimentation. > > There should be a number of mails on the subject in the archives of the > scsi mailing list, look for myself or greg lehay to find the thread. > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message