From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: Thin provisioning & arrays Date: Mon, 10 Nov 2008 06:30:11 -0700 Message-ID: <20081110133010.GN15439@parisc-linux.org> References: <4913028B.6010405@redhat.com> <1225984628.4703.80.camel@localhost.localdomain> <20081107120534.GO21867@kernel.dk> <1226072970.15281.46.camel@think.oraclecorp.com> <20081109233639.GT4985@disturbed> <9FA859626025B64FBC2AF149D97C944A8A648D@CORPUSMX80A.corp.emc.com> <20081110083126.GF2373@disturbed> <1226311189.4367.30.camel@macbook.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dave Chinner , Black_David@emc.com, martin.petersen@oracle.com, chris.mason@oracle.com, jens.axboe@oracle.com, James.Bottomley@hansenpartnership.com, rwheeler@redhat.com, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, coughlan@redhat.com To: David Woodhouse Return-path: Content-Disposition: inline In-Reply-To: <1226311189.4367.30.camel@macbook.infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, Nov 10, 2008 at 10:59:49AM +0100, David Woodhouse wrote: > Storage devices are complex enough that they _already_ exhibit behaviour > which is fairly much non-deterministic in a number of ways. Especially > if we're talking about SSDs or large arrays, rather than just disks. If anything, SSDs are more deterministic than rotating storage. Variable numbers of sectors per track, unpredictable sector remapping, track re-reads due to errors during reads ... SSDs seem like a real improvement. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."