From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Tso Subject: Re: thin provisioned LUN support Date: Fri, 7 Nov 2008 14:35:03 -0500 Message-ID: <20081107193503.GG29717@mit.edu> References: <20081107120534.GO21867@kernel.dk> <1226072970.15281.46.camel@think.oraclecorp.com> <1226074002.8030.33.camel@localhost.localdomain> <1226074270.15281.50.camel@think.oraclecorp.com> <1226074710.8030.43.camel@localhost.localdomain> <1226078535.15281.63.camel@think.oraclecorp.com> <4914846C.5060103@redhat.com> <20081107183636.GB29717@mit.edu> <49148BDF.9050707@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Chris Mason , James Bottomley , "Martin K. Petersen" , Jens Axboe , David Woodhouse , linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, Black_David@emc.com, Tom Coughlan , Matthew Wilcox To: Ric Wheeler Return-path: Received: from www.church-of-our-saviour.ORG ([69.25.196.31]:47818 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751358AbYKGTfZ (ORCPT ); Fri, 7 Nov 2008 14:35:25 -0500 Content-Disposition: inline In-Reply-To: <49148BDF.9050707@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Nov 07, 2008 at 01:41:35PM -0500, Ric Wheeler wrote: >> Will we be able to query the device and find out its TRIM/UNMAP >> alignment requirements? There is also a balanace between performance >> (at least if the concern is sending too many separate TRIM commands) >> and giving the SSD more flexibility in its wear-leveling allocation >> decisions by sending TRIM commands sooner rather than later. >> > > T10 is still working on the proposal for how to display unmap related > information for SCSI, so we don't even have a consistent way to find > this out today for this population. Yeah, I know, the rhetorical question was mostly addressed at David Black. :-) > Not sure what is possible for the ATA devices, I thought ATA didn't have any TRIM alignment requirements, and it's T10 that wants to add it to the SCSI side? - Ted