This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


RE: [Xen-devel] Should "xm restore" be able to create two domains with t

To: "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>, "xen-devel" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Should "xm restore" be able to create two domains with the same name?
From: "Petersson, Mats" <Mats.Petersson@xxxxxxx>
Date: Fri, 18 May 2007 16:19:53 +0200
Delivery-date: Fri, 18 May 2007 07:18:35 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C2736EDA.F2A1%Keir.Fraser@xxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AceZU2xSKqeqRq69R4u5QdmVPAVOfAAAMEA1AAAewOA=
Thread-topic: [Xen-devel] Should "xm restore" be able to create two domains with the same name?

> -----Original Message-----
> From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx] 
> Sent: 18 May 2007 14:55
> To: Petersson, Mats; xen-devel
> Subject: Re: [Xen-devel] Should "xm restore" be able to 
> create two domains with the same name?
> On 18/5/07 14:49, "Petersson, Mats" <Mats.Petersson@xxxxxxx> wrote:
> > If I do "xm save dom file", followed by "xm restore file; xm restore
> > file", I get two domains with the same name. Surely, that's 
> not quite
> > right? [Particularly since they both will be using the same 
> disk-image,
> > etc]. 
> You shouldn't do that. ;-)

Yes, I _KNOW THAT_. But as you may be aware, I'm not infallible
(unfortunately, I have FAR too much evidence of my fallibility) - and I
expect other people using Xen may not be either ;-) [In this case, I
didn't realize I had already done a restore after rebooting the system -
because I don't have ANY display on the actual domain, and I only
realized after I did "xm list" a while later.]

> The second restore ought to fail when xend (or the hotplug 
> scripts) realise
> that the block device is already in use.

Yes, it does (I realize after reading the xend.log). But the error isn't
reported back to the user, and the domain is still kept alive after it's
been refused access to the disk. 

But I'm also concerned that if I try "xm create" with the same name
twice, it complains that the domain already exists. Should "xm restore"
do the same check to see if a domain by that name already exists and
stop creating the second same-name-instance?

Further, I have two SLES9.3 HVM domains that I've successfully logged
into  - they are distinctly different domains, but using the same single
SLES9.3 image that I've got [this was an INTENTIONAL attempt to make
this happne, rather than an accident the first time round]. I'm not sure
why xend didn't discover that this wasn't going to work. 

I just saw Dan's post on the ability to create multiple instances, so
obviously, this has changed relatively recently... 

>  -- Keir

Xen-devel mailing list