From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: What runtime states to be preserved across save / restore? Date: Tue, 29 Apr 2014 11:42:51 +0100 Message-ID: <20140429104251.GF28126@zion.uk.xensource.com> References: <20140428131041.GA28126@zion.uk.xensource.com> <1398692533.29700.108.camel@kazak.uk.xensource.com> <20140428135716.GB28126@zion.uk.xensource.com> <1398694577.29700.130.camel@kazak.uk.xensource.com> <20140429072910.GA22475@router-fw-old.local.net-space.pl> <20140429090526.GE28126@zion.uk.xensource.com> <20140429104015.GA24919@router-fw-old.local.net-space.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20140429104015.GA24919@router-fw-old.local.net-space.pl> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Daniel Kiper Cc: Wei Liu , Ian Campbell , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Tue, Apr 29, 2014 at 12:40:15PM +0200, Daniel Kiper wrote: > On Tue, Apr 29, 2014 at 10:05:26AM +0100, Wei Liu wrote: > > On Tue, Apr 29, 2014 at 09:29:10AM +0200, Daniel Kiper wrote: > > > On Mon, Apr 28, 2014 at 03:16:17PM +0100, Ian Campbell wrote: > > > > On Mon, 2014-04-28 at 14:57 +0100, Wei Liu wrote: > > > > > > > > > > Other things I can think of right now: > > > > > > > > > > > > * The devid of each device -- for some classes these can be > > > > > > automatically assigned, I'm not really sure if that needs > > > > > > preserving or not. > > > > > > > > > > I don't think so. The receiving end should make its own decision. > > > > > > > > Having eth0 become eth1 over migrate would be surprising though, > > > > wouldn't it? > > > > > > > > > > * Hotplug of devices more generally > > > > > > > > > > > > > > > > Scripts? If so, they, with the things you mentioned below ... > > > > > > > > Not script, I meant e.g. xl block-attach and stuff like that. > > > > > > Do not forget about memory hotplug and in general memory != maxmem. > > > This stuff is also important in migration case. > > > > > > > I think max memory and target memory are easy -- I can retrieve them > > from xenstore. But where can I get information about memory hotplug? > > If the relevant bits are missing in libxl then I think we need another > > series to address this problem. > > I think that target and max memory should be sufficient. I mentioned Cool! > about that because when I tested migration with xm a few years ago > I was not able to migrate machine which had hotplugged memory. IIRC > it happened because migration process refered to config file instead > of checking relevant values in xenstore. Acording to my knowledge save > and restore machinery is (or was) used for migration. Correct me > if I am wrong. > You're right about this. ;-) Wei. > Daniel