From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: Are there plans to achieve ram live Snapshot feature? Date: Fri, 09 Aug 2013 10:45:22 -0500 Message-ID: <877gfu3m25.fsf@codemonkey.ws> References: <33FB050264B7AD4DBD6583581F2E03104B764728@nkgeml511-mbx.china.huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Chijianchun , "paul\@codesourcery.com" , "kvm\@vger.kernel.org" , "avi\@redhat.com" , "mtosatti\@redhat.com" , "qemu-devel\@nongnu.org" Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:41693 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964975Ab3HIPpb (ORCPT ); Fri, 9 Aug 2013 11:45:31 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 9 Aug 2013 09:45:31 -0600 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id C5FEC6E8040 for ; Fri, 9 Aug 2013 11:45:22 -0400 (EDT) Received: from d01av05.pok.ibm.com (d01av05.pok.ibm.com [9.56.224.195]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r79FjSXK32768028 for ; Fri, 9 Aug 2013 11:45:28 -0400 Received: from d01av05.pok.ibm.com (loopback [127.0.0.1]) by d01av05.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r79FjRrc027684 for ; Fri, 9 Aug 2013 11:45:27 -0400 In-Reply-To: <33FB050264B7AD4DBD6583581F2E03104B764728@nkgeml511-mbx.china.huawei.com> Sender: kvm-owner@vger.kernel.org List-ID: Chijianchun writes: > Now in KVM, when RAM snapshot, vcpus needs stopped, it is Unfriendly restrictions to users. > > Are there plans to achieve ram live Snapshot feature? I think you mean a live version of the savevm command. You can approximate live migrating to a file, creating an external disk snapshot, then resuming the guest. Regards, Anthony Liguori > > in my mind, Snapshots can not occupy additional too much memory, So when the memory needs to be changed, the old memory page is needed to flush to the file first. But flushing to file is too slower than memory, and when flushing, the vcpu or VM is need to be paused until finished flushing, so pause...resume...pause...resume............., more and more slower. > > Is this idea feasible? Are there any other thoughts? From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36644) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7oso-0005nI-KZ for qemu-devel@nongnu.org; Fri, 09 Aug 2013 11:45:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V7osg-0004Uk-C4 for qemu-devel@nongnu.org; Fri, 09 Aug 2013 11:45:42 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:54518) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7osg-0004U5-8E for qemu-devel@nongnu.org; Fri, 09 Aug 2013 11:45:34 -0400 Received: from /spool/local by e7.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 9 Aug 2013 11:45:31 -0400 Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 0237D38C803B for ; Fri, 9 Aug 2013 11:45:28 -0400 (EDT) Received: from d01av05.pok.ibm.com (d01av05.pok.ibm.com [9.56.224.195]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r79FjRei31260772 for ; Fri, 9 Aug 2013 11:45:27 -0400 Received: from d01av05.pok.ibm.com (loopback [127.0.0.1]) by d01av05.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r79FjRrY027684 for ; Fri, 9 Aug 2013 11:45:27 -0400 From: Anthony Liguori In-Reply-To: <33FB050264B7AD4DBD6583581F2E03104B764728@nkgeml511-mbx.china.huawei.com> References: <33FB050264B7AD4DBD6583581F2E03104B764728@nkgeml511-mbx.china.huawei.com> Date: Fri, 09 Aug 2013 10:45:22 -0500 Message-ID: <877gfu3m25.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Subject: Re: [Qemu-devel] Are there plans to achieve ram live Snapshot feature? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Chijianchun , "paul@codesourcery.com" , "kvm@vger.kernel.org" , "avi@redhat.com" , "mtosatti@redhat.com" , "qemu-devel@nongnu.org" Chijianchun writes: > Now in KVM, when RAM snapshot, vcpus needs stopped, it is Unfriendly restrictions to users. > > Are there plans to achieve ram live Snapshot feature? I think you mean a live version of the savevm command. You can approximate live migrating to a file, creating an external disk snapshot, then resuming the guest. Regards, Anthony Liguori > > in my mind, Snapshots can not occupy additional too much memory, So when the memory needs to be changed, the old memory page is needed to flush to the file first. But flushing to file is too slower than memory, and when flushing, the vcpu or VM is need to be paused until finished flushing, so pause...resume...pause...resume............., more and more slower. > > Is this idea feasible? Are there any other thoughts?