RE: Re: xend issues

RE: Re: xend issues

[Neugebauer, Rolf]

> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-
> bounces@lists.xensource.com] On Behalf Of Arun Sharma
> Sent: 15 June 2005 21:47
> To: xen-devel
> Subject: [Xen-devel] Re: xend issues
> 
> Arun Sharma wrote:
> >
> > Lately, I'm having trouble destroying VMX domains (probably due to
bad
> > reference counts) - although all memory associated with the domain
is
> > freed up.
> >
> > Subsequently, if I create a new domain of the same name, the domain
id
> > is wrong.
> >
> > # xm list
> > Name              Id  Mem(MB)  CPU VCPU(s)  State  Time(s)  Console
> > Domain-0           0      245    0      1   r----     50.8
> > ExampleVMXDomain   1        0    0      1   -----     22.5     9601
> > ExampleVMXDomain   1        0    0      1   -----     22.5     9601
> >
> > Even the uuid of the two domains is the same in the long listing
below.
> 
> BTW, this issue doesn't happen if I use a different name for the new
> domain (xm create name=foo). Normally xend doesn't let me create two
> domains with the same name. But in this case, it does let me do it and
> then gets confused about domain ids and uuids.

I haven't had the issue with two vms with the same name and same ID,
but, my experience is that the VMX domains linger around till you
forcible (-9) kill the device model.

Clearly this is something which needs to be addressed in xend as it
should have the info avail to destroy the device model when the vmx
domain goes away.

On a related note, currently the VNC viewer for the VMX domain is
started by xend but in my opinion should be started by 'xm' (as with
native xen VMs) as you are more likely to have your DISPLAY/XAUTH set
when executing xm rather than when xend is started.

Rolf

> 	-Arun
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: Re: xend issues

[Arun Sharma]

Neugebauer, Rolf wrote:

> 
>>BTW, this issue doesn't happen if I use a different name for the new
>>domain (xm create name=foo). Normally xend doesn't let me create two
>>domains with the same name. But in this case, it does let me do it and
>>then gets confused about domain ids and uuids.
> 
> 
> I haven't had the issue with two vms with the same name and same ID,
> but, my experience is that the VMX domains linger around till you
> forcible (-9) kill the device model.
> 

In the last few days, this happens even after kill -9.

	-Arun

Re: Re: xend issues

[Mike Wray]

Arun Sharma wrote:
> Arun Sharma wrote:
> 
>>
>> Lately, I'm having trouble destroying VMX domains (probably due to bad 
>> reference counts) - although all memory associated with the domain is 
>> freed up.
>>
>> Subsequently, if I create a new domain of the same name, the domain id 
>> is wrong.
>>
>> # xm list
>> Name              Id  Mem(MB)  CPU VCPU(s)  State  Time(s)  Console
>> Domain-0           0      245    0      1   r----     50.8
>> ExampleVMXDomain   1        0    0      1   -----     22.5     9601
>> ExampleVMXDomain   1        0    0      1   -----     22.5     9601
>>
>> Even the uuid of the two domains is the same in the long listing below.

This may be due to a xend 'feature'. When deciding whether there is a vm name clash,
xend ignores 'dead' domains, so that zombies don't stop you reusing the name.
Since the ExampleVMXDomain has mem 0 I'd guess it's been destroyed but
refused to die. The duplicate ids are a puzzle though, since the xend domain
map is indexed by domain id.

The kernel cleanup for VMX domains in xend releases the device model event channel -
but it seems from another message that the device model is not using the port
that xend has, but another one. This might account for the domain refusing to go
away - open event channels will do that.

> BTW, this issue doesn't happen if I use a different name for the new 
> domain (xm create name=foo). Normally xend doesn't let me create two 
> domains with the same name. But in this case, it does let me do it and 
> then gets confused about domain ids and uuids.

Mike