From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id n974esn6160969 for ; Tue, 6 Oct 2009 23:40:55 -0500 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 1FD464A9319 for ; Tue, 6 Oct 2009 21:42:19 -0700 (PDT) Received: from mail.internode.on.net (bld-mail13.adl6.internode.on.net [150.101.137.98]) by cuda.sgi.com with ESMTP id 1Yee9rBYa7urPu34 for ; Tue, 06 Oct 2009 21:42:19 -0700 (PDT) Date: Wed, 7 Oct 2009 15:42:16 +1100 From: Dave Chinner Subject: Re: [PATCH] mkfs: add discard support Message-ID: <20091007044215.GK9464@discord.disaster> References: <20091006184758.GA4780@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20091006184758.GA4780@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Tue, Oct 06, 2009 at 02:47:58PM -0400, Christoph Hellwig wrote: > Call the BLKDISCARD ioctl to mark the whole disk as unused before creating > a new filesystem. This will allow SSDs, Arrays with thin provisioning support > and virtual machines to make smarter allocation decisions. Good idea, but perhaps the discard should be optional rather than unconditional. My immediate thought was the SOP for setting up encrypted devices - fill the empty disk with random data before setting up the encrypted device. If you then send it a discard.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs