From owner-freebsd-hackers Mon Aug 2 23: 0:34 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from mail.du.gtn.com (mail.du.gtn.com [194.77.9.57]) by hub.freebsd.org (Postfix) with ESMTP id 2B5FA14F97 for ; Mon, 2 Aug 1999 23:00:23 -0700 (PDT) (envelope-from ticso@cicely8.cicely.de) Received: from cicely7.cicely.de (cicely.de [194.231.9.142]) by mail.du.gtn.com (8.8.6/8.8.6) with ESMTP id HAA28876; Tue, 3 Aug 1999 07:47:56 +0200 (MET DST) Received: from cicely8.cicely.de (cicely8.cicely.de [10.1.2.10]) by cicely7.cicely.de (8.9.0/8.9.0) with ESMTP id HAA52270; Tue, 3 Aug 1999 07:47:25 +0200 (CEST) Received: (from ticso@localhost) by cicely8.cicely.de (8.9.3/8.9.2) id HAA24235; Tue, 3 Aug 1999 07:48:10 +0200 (CEST) (envelope-from ticso) Date: Tue, 3 Aug 1999 07:48:10 +0200 From: Bernd Walter To: Greg Lehey Cc: Stephen Hocking-Senior Programmer PGS Tensor Perth , hackers@FreeBSD.ORG, shocking@bandicoot.prth.tensor.pgs.com Subject: Re: Adding disks -the pain. Also vinum Message-ID: <19990803074809.A23148@cicely8.cicely.de> References: <199908030311.LAA16741@ariadne.tensor.pgs.com> <19990803133554.S62948@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.3i In-Reply-To: <19990803133554.S62948@freebie.lemis.com>; from Greg Lehey on Tue, Aug 03, 1999 at 01:35:54PM +0930 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Aug 03, 1999 at 01:35:54PM +0930, Greg Lehey wrote: > On Tuesday, 3 August 1999 at 11:11:39 +0800, Stephen Hocking-Senior Programmer PGS Tensor Perth wrote: > > No, it would cause a higher I/O load. Vinum doesn't transfer entire > stripes, it transfers what you ask for. With a large stripe size, the > chances are higher that you can perform the transfer with only a > single I/O. > If you use n*64K stripes a UFS/FFS should never access 2 disks at once. > > Looking at the systat display, the 8k fs blocks do seem to be > > clustered into larger requests, so I'm not too worried about the FS > > block size. What have people observed with trying larger FS block > > sizes? > > I don't know if anybody has tried larger FS blocks than 8 kB. I once > created a file system with 256 kB blocks (just to see if it could be > done). I also tried 512 kB blocks, but newfs died of an overflow. > I'd expect that you would see a marked drop in performance, assuming > that it would work at all. AFAIK the limit is 64k because clustering is limitited to 64k and the fs don't seem to handle it well. I'm using 64k very often, because my growfs tool is already able with this blocksize to grow a ffs over 1Tb. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message