xend issues

xend issues

[Arun Sharma]

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.

	-Arun

# xm list --long
(domain
     (id 0)
     (name Domain-0)
     (memory 245)
     (uuid 7a8af663-b55c-46cf-bd24-dc65e3e17a83)
     (maxmem -4)
     (state r----)
     (cpu 0)
     (cpu_time 51.166374782)
     (vcpus 1)
     (cpumap (-1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0))
     (vcpu_to_cpu 0)
)
(domain
     (id 1)
     (name ExampleVMXDomain)
     (memory 0)
     (uuid ad91cc37-0fb6-4c20-a01c-f38fedb7aafc)
     (maxmem 131204)
     (state -----)
     (cpu 0)
     (cpu_time 22.537481777)
     (vcpus 1)
     (cpumap (-1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0))
     (vcpu_to_cpu 0)
     (up_time 4798.9793551)
     (start_time 1118863256.58)
     (console
         (status closed)
         (id 0)
         (domain 1)
         (local_port 0)
         (remote_port 0)
         (console_port 9601)
     )
     (devices
         (console
             (status closed)
             (id 0)
             (domain 1)
             (local_port 0)
             (remote_port 0)
             (console_port 9601)
         )
     )
     (config
         (vm
             (name ExampleVMXDomain)
             (memory 128)
             (image
                 (vmx
                     (kernel /usr/lib/xen/boot/vmxloader)
                     (root '/dev/hda1 ro')
                     (args
                         'VNC_VIEWER=143.183.130.223:5501 acpi=off 
console=ttyS0
1'
                     )
                     (vcpus 1)
                 )
             )
             (memmap /etc/xen/mem-map.sxp)
             (device_model /usr/bin/device-model)
             (device_config /etc/xen/xmexample.vmx)
         )
     )
)
(domain
     (id 1)
     (name ExampleVMXDomain)
     (memory 0)
     (uuid ad91cc37-0fb6-4c20-a01c-f38fedb7aafc)
     (maxmem 131204)
     (state -----)
     (cpu 0)
     (cpu_time 22.537481777)
     (vcpus 1)
     (cpumap (-1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0))
     (vcpu_to_cpu 0)
     (up_time 4799.01007318)
     (start_time 1118863256.58)
     (console
         (status closed)
         (id 0)
         (domain 1)
         (local_port 0)
         (remote_port 0)
         (console_port 9601)
     )
     (devices
         (console
             (status closed)
             (id 0)
             (domain 1)
             (local_port 0)
             (remote_port 0)
             (console_port 9601)
         )
     )
     (config
         (vm
             (name ExampleVMXDomain)
             (memory 128)
             (image
                 (vmx
                     (kernel /usr/lib/xen/boot/vmxloader)
                     (root '/dev/hda1 ro')
                     (args
                         'VNC_VIEWER=143.183.130.223:5501 acpi=off 
console=ttyS01'
                     )
                     (vcpus 1)
                 )
             )
             (memmap /etc/xen/mem-map.sxp)
             (device_model /usr/bin/device-model)
             (device_config /etc/xen/xmexample.vmx)
         )
     )
)

Re: xend issues

[Arun Sharma]

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.

	-Arun

Re: xend issues

[Leendert van Doorn]

Neugebauer, Rolf wrote:

# 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.

Amen!

This is why I added VMX support to vmtools. It allowed me to create the
device model from the controlling terminal so that it would have access
to the user's environment and it even allowed me to pass options to qemu
such as "-monitor stdio" so I could issue "change cdrom ..."  commands.

Alas, the developers of vmtools have (temporarily?) dropped vmx support
from vmtools and the old version is incompatible with the latest version
of Xen.  I'm now forced to use xm/xend as well :-( :-(

	Leendert

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