From: Ted Ts'o Subject: Re: I/O topology fixes for big physical block size Date: Thu, 30 Sep 2010 12:30:47 -0400 Message-ID: <20100930163047.GA4098@thunk.org> References: <4CA118FF.1080100@fusionio.com> <20100927231551.GA15653@redhat.com> <4CA16F6A.1090904@fusionio.com> <4CA17B13.7080801@redhat.com> <20100928141545.GA21587@redhat.com> <20100928205741.GA22257@thunk.org> <4CA25FEA.6040505@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Martin K. Petersen" , Mike Snitzer , Jens Axboe , "James.Bottomley@hansenpartnership.com" , "linux-scsi@vger.kernel.org" , "linux-ext4@vger.kernel.org" To: Eric Sandeen Return-path: Received: from thunk.org ([69.25.196.29]:53702 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754995Ab0I3QbA (ORCPT ); Thu, 30 Sep 2010 12:31:00 -0400 Content-Disposition: inline In-Reply-To: <4CA25FEA.6040505@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Sep 28, 2010 at 04:36:42PM -0500, Eric Sandeen wrote: > Ok, then it sounds like mkfs.ext4's refusal to make fs blocksize less > than device physical sectorsize without -F is broken, and that should > be removed. I'd say issue a warning in the case but if there's a 16k > physical device maybe there's no point in warning either? If the device physical sectorsize is that big, should we perhaps use that as a hint to align writes to that blocks aligned with that physical sectorsize? Right now we use the optimal I/O size, but if the optimal I/O size is not specified and the physical sectorsize is, say, 16k or 32k, maybe we should use to calculate for s_raid_stripe_width? - Ted