From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH 0 of 3] [RFC] I/O Hints Date: Fri, 6 Jun 2008 15:26:13 +0100 Message-ID: <20080606142613.GA22495@shareable.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org To: "Martin K. Petersen" Return-path: Received: from mail2.shareable.org ([80.68.89.115]:50379 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798AbYFFO0O (ORCPT ); Fri, 6 Jun 2008 10:26:14 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Martin K. Petersen wrote: > Comments and suggestions are welcome. Flash devices and SSDs (solid-state storage) in general are becoming more common. Also, backing a disk with flash. And increasingly people will stripe, parity, mirror or concatenate disks and flash just because it's convenient. --> So it would be nice if some of the flash alignment characteristics could be reported. Some aspects of flash don't fit into block devices - e.g. erase block and write order requirements. That's MTD stuff, not appropriate here. But SSDs present a block device interface, and they still have alignment characteristics for performance. Even more important, when combining multiple SSDs into a RAID. -- Jamie