From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:47072) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qofuz-00005m-4F for qemu-devel@nongnu.org; Wed, 03 Aug 2011 14:11:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qofux-0004kr-LY for qemu-devel@nongnu.org; Wed, 03 Aug 2011 14:11:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18563) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qofux-0004kg-DP for qemu-devel@nongnu.org; Wed, 03 Aug 2011 14:11:43 -0400 Date: Wed, 3 Aug 2011 15:11:38 -0300 From: Luiz Capitulino Message-ID: <20110803151138.28850d1c@doriath> In-Reply-To: <20110803163131.GA8411@lst.de> References: <1312384765-721-1-git-send-email-lcapitulino@redhat.com> <20110803163131.GA8411@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 0/5]: QMP: Proper thin provisioning support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoph Hellwig Cc: kwolf@redhat.com, aliguori@us.ibm.com, qemu-devel@nongnu.org, armbru@redhat.com On Wed, 3 Aug 2011 18:31:31 +0200 Christoph Hellwig wrote: > > It's already possible for QMP clients to implement this feature by using > > the BLOCK_IO_ERROR event. However, the event can be missed. When this > > happens QMP clients need a way to query if any block device has hit a > > no space condition. > > We have a mode where we stop the VM when it hits ENOSPC, and that is > the only reliably way to handle it. This series just complements that mode by allowing a mngt application to query which device triggered the ENOSPC. Well, that's my intention :) > One that ENOSPC gets returned > to the guest we don't know that it was an ENOSPC, and the guest will > usually simply shut the filesystem down. This could be worked around > by implementing full T10 logical provisioning support, but very few > guests actually support it properly. And it won't work with ide disks > at all, and for virtio we'd have to implement it first. Seems interesting, but the current solution is guest independent.