From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47599) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fhver-0007b8-GY for qemu-devel@nongnu.org; Tue, 24 Jul 2018 07:39:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fhven-0001yK-Jf for qemu-devel@nongnu.org; Tue, 24 Jul 2018 07:39:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48808 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fhven-0001yD-Ea for qemu-devel@nongnu.org; Tue, 24 Jul 2018 07:39:09 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EFB9A77888 for ; Tue, 24 Jul 2018 11:39:08 +0000 (UTC) Date: Tue, 24 Jul 2018 19:39:04 +0800 From: Peter Xu Message-ID: <20180724113904.GC2479@xz-mi> References: <20180723123305.24792-1-peterx@redhat.com> <20180723123305.24792-3-peterx@redhat.com> <877ellgf9w.fsf@secure.mitica> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <877ellgf9w.fsf@secure.mitica> Subject: Re: [Qemu-devel] [PATCH for-3.0 2/4] migration: disallow recovery for release-ram List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: qemu-devel@nongnu.org, "Dr . David Alan Gilbert" On Tue, Jul 24, 2018 at 11:21:47AM +0200, Juan Quintela wrote: > Peter Xu wrote: > > Postcopy recovery won't work well with release-ram capability since > > release-ram will drop the page buffer as long as the page is put into > > the send buffer. So if there is a network failure happened, any page > > buffers that have not yet reached the destination VM but have already > > been sent from the source VM will be lost forever. Let's refuse the > > client from resuming such a postcopy migration. Luckily release-ram was > > designed to only be used when src and destination VMs are on the same > > host, so it should be fine. > > > > Signed-off-by: Peter Xu > > Reviewed-by: Juan Quintela Thanks. > > I wonder if we should have a FAQ somewhere and point an URL to there. Yeah we possibly should. I have plan to write up a postcopy recovery wiki page, maybe an addon to the old postcopy wiki page, but I haven't yet started (especially after knowing that libvirt developers know well about how to use it already, hence I put that a lower priority...). Regards, -- Peter Xu