From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:46798) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S5v4C-0003gn-Bp for qemu-devel@nongnu.org; Fri, 09 Mar 2012 03:20:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S5v47-0000gJ-Rp for qemu-devel@nongnu.org; Fri, 09 Mar 2012 03:20:47 -0500 Received: from parsec.stupidest.org ([71.6.196.126]:53754) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S5v47-0000g7-M6 for qemu-devel@nongnu.org; Fri, 09 Mar 2012 03:20:43 -0500 Date: Fri, 9 Mar 2012 00:20:41 -0800 From: Chris Wedgwood Message-ID: <20120309082041.GA28158@puku.stupidest.org> References: <1331226917-6658-1-git-send-email-pbonzini@redhat.com> <1331226917-6658-15-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331226917-6658-15-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH 14/17] block: support FALLOC_FL_PUNCH_HOLE trimming List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org > This will enable discard on more filesystems, including ext4. i think this should default to off for preallocated files this will punch holes all over the place and reallocation will cause fragmentation (guests will free and reallocat blocks normally) xfs has a mechanism to convert to unwritten extents that would avoid that, but it's not implemented in other filesystems