From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:46341) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Si7yf-0003D6-Ui for qemu-devel@nongnu.org; Fri, 22 Jun 2012 13:49:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Si7yd-0002eL-P2 for qemu-devel@nongnu.org; Fri, 22 Jun 2012 13:49:01 -0400 Received: from parsec.stupidest.org ([71.6.196.126]:39059) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Si7yd-0002dv-Ic for qemu-devel@nongnu.org; Fri, 22 Jun 2012 13:48:59 -0400 Date: Fri, 22 Jun 2012 10:48:56 -0700 From: Chris Wedgwood Message-ID: <20120622174856.GA6505@puku.stupidest.org> References: <1340319857-28198-1-git-send-email-mdroth@linux.vnet.ibm.com> <1340319857-28198-3-git-send-email-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1340319857-28198-3-git-send-email-mdroth@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH 2/2] qemu-ga: add guest-fstrim command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Roth Cc: pbonzini@redhat.com, aliguori@us.ibm.com, qemu-devel@nongnu.org > FITRIM is a mounted filesystem feature to discard (or "trim") blocks which > are not in use by the filesystem. This is useful for solid-state drives > (SSDs) and thinly-provisioned storage. Provide access to the feature > from the host so that filesystems can be trimmed periodically or before > migration. Why can't we use the block layer for this? AHCI (I think) already has support, others could be added some some coordination. That was existing operating systems with current filesystems will DTRT when needed.