From owner-freebsd-fs Tue Mar 27 16:53: 9 2001 Delivered-To: freebsd-fs@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id BB19437B718; Tue, 27 Mar 2001 16:53:01 -0800 (PST) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id E4DF36A90D; Wed, 28 Mar 2001 10:22:59 +0930 (CST) Date: Wed, 28 Mar 2001 10:22:59 +0930 From: Greg Lehey To: Alfred Perlstein Cc: Brandon Gale , "Michael C . Wu" , dillon@FreeBSD.ORG, fs@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: Vinum stripe size (was: tuning a VERY heavily (30.0) loaded server) Message-ID: <20010328102259.B92853@wantadilla.lemis.com> References: <20010327181141.H1161@wantadilla.lemis.com> <20010328095143.N1161@wantadilla.lemis.com> <20010327163833.O9431@fw.wintelcom.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010327163833.O9431@fw.wintelcom.net>; from bright@wintelcom.net on Tue, Mar 27, 2001 at 04:38:33PM -0800 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tuesday, 27 March 2001 at 16:38:33 -0800, Alfred Perlstein wrote: > * Greg Lehey [010327 16:21] wrote: >> On Tuesday, 27 March 2001 at 17:59:23 -0500, Brandon Gale wrote: >>>>> Do you think it'd be worth it to have vinum carp about what may >>>>> be a non optimal stripe size? >>>>> >>>>> "Warning N is probably a bad idea for a stripe size, see docs" >>>> >>>> Only if it can recognize the fact correctly. >>> >>> How about even having vinum recommend something? >> >> I'm open to code suggestions. The problem is that by the time you >> create it, it's too late. > > That's not true. For a certain definition of "too late", maybe not. > By the time you've newfs'd it, stored data on it and deployed it > into production it's too late. It's certainly later then. > Right after you make the volume is a good time to print out a little > banner telling them to check the docs, something like: > > "WARNING: selecting a stripe size can be tricky, you really should > see the vinum(8) manpage specifically the section about FOO for > suggestions for optimal stripe sizes." Yes, but then you've already selected your stripe size. About the best I can think of would be a utility function which calculates the stripe size based on the number of subdisks, the total size and the cylinder group size. You could then do something like plex org striped without the stripe size, and let vinum(8) decide the stripe size for you. As I said, code submissions welcome :-) Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message