From owner-freebsd-hackers Thu Jun 17 2: 2:28 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (Postfix) with ESMTP id 785BB150F5 for ; Thu, 17 Jun 1999 02:02:21 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id SAA03887; Thu, 17 Jun 1999 18:32:20 +0930 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id SAA52465; Thu, 17 Jun 1999 18:32:26 +0930 (CST) Date: Thu, 17 Jun 1999 18:32:25 +0930 From: Greg Lehey To: Ville-Pertti Keinonen Cc: "David E. Cross" , hackers@FreeBSD.ORG Subject: Re: vinum performance Message-ID: <19990617183225.Q9893@freebie.lemis.com> References: <199906170743.DAA16929@cs.rpi.edu> <86so7rqkdg.fsf@not.demophon.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <86so7rqkdg.fsf@not.demophon.com>; from Ville-Pertti Keinonen on Thu, Jun 17, 1999 at 11:52:43AM +0300 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 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thursday, 17 June 1999 at 11:52:43 +0300, Ville-Pertti Keinonen wrote: > > crossd@cs.rpi.edu (David E. Cross) writes: > >> I have a drive that is rated at ~16 Meg/second, and indeed it delivers on the >> order of 15+ Meg/second. If I use Vinum to create a concatinated device >> of 2 such units performance drops to 2.5 Meg/sec. This seems like a >> drastic drop in performance. Any ideas what I am doin incorrectly? > > You've accidentally striped subdisks on the same drive? ;--) > > Like Greg Lehey said, you haven't really provided enough details. He did provide one detail, though; this is a concatenated plex, not a striped one. > The minimum info required would be: > > - Is this read or write performance? That wouldn't be enough. > Many disks are shipped with write caching disabled, and write > performance can be significantly worse than read performance. Not if it works without Vinum. > - Are you testing through the filesystem? (How are you testing?) That's the real qustion. > Maybe you're doing a dd test and accessing /dev/vinum/vol/* rather > than /dev/vinum/rvol/*... That would, in fact, be faster. But we need to know what he's doing, and I suspect you're on the right track. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message