Daniel Veillard wrote:
> On Fri, Aug 10, 2007 at 12:36:05PM -0400, Jim Paris wrote:
> > I think appending unrelated data to the migration image is a bit of a
> > hack anyway. A better plan would be a file containing
> > <header> <XML config> <migration data>
>
> Hum, beware you then need to make sure that you indicate in the
> header the lenght of the XML config, because you can't ask the XML parser
> to tell you when the XML file ends. Should not be hard but it's a pitfall
> I have seen too many people trip on :-)
Remembering to null-terminate the XML config before passing it to
qemudParseVMDef is also helpful :)
I have it mostly working now. Saving works fine, but restoring is a
bit buggy with regards to multiple copies of the same domain, config
files, etc. This is what I'm using for resuming:
xml = read XML
def = qemudParseVMDef(xml)
vm = qemudAssignVMDef(def)
if (qemudStartVMDaemon(vm) < 0)
qemudRemoveInactiveVM(vm)
My questions:
Should I add qemudSaveVMDef somewhere? Currently, if I undefine a
domain and then restore from an image, I don't think there's any way
to then save that domain back to a config file.
What should happen if one tries to resume the same image twice?
Currently I think qemudAssignVMDef returns a pointer to the first vm,
the start fails, and then RemoveInactiveVM removes the running one --
not good. Should I try to detect when the name/UUID already exists
and refuse?
The "test" driver seems to also be broken in this regard:
$ virsh --connect test:///default
virsh > save test /tmp/test
virsh > restore /tmp/test
virsh > shutdown 2
virsh > list --all
Id Name State
----------------------------------
- test shut off
- test shut off
There's no way to uniquely refer to either of those now.
Does the xen driver handle this any better?
Also, is there a reason qemudAssignVMDef match by name rather than
UUID? Are names supposed to be unique?
-jim
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