[Libvir] [PATCH]Reprt error for a existing file

[Richard W.M. Jones]

Kazuki Mizushima wrote:
> Hi,
> 
>> under layer, XenD or so. I'II try to put this into XenD.
> 
> 
> I tried to put xen community, it rejects.

[For reference, here is the thread on xen-devel]
http://lists.xensource.com/archives/html/xen-devel/2007-03/threads.html#00298

> Though I am understanding follwing, Isn't there something good way ?
> 
>>> There is really no way virsh/libvirt can reliably check for dump
>>> or save file existance - only XenD or QEMU can do that. So if we want
> 
> If this goes on, for user managing services by using virsh/libvirt,
> there is no way to recover for the user.
> 
> For example, save file(maybe used as backup file) is overwritten without 
> any confirmation, I suspect that user confuses about the one different 
> from expected OS starting.
> 
> Surely, although it is a user's mistake, I want to solve this by saying 
> a confirmation like a below, so that user can confirm it once.
> 
>  # virsh save <domain> <file>
>    save: save file  "<file>"?
>  #
> 
>  # virsh dump <domain> <file>
>    dump: dump file "<file>"?
>  #
> 
> How do you think about this?

There's not a "good" way to solve this without support in XenD.

The question is are there bad ways to solve this in libvirt or virsh. 
What do people think about having an optional flag in virsh, like:

   virsh save --no-clobber <domain> <file>

Unfortunately if we add support for this flag into libvirt then we 
either have to break ABI compatibility or else have to add a new call. 
Neither is pleasant.

Or we could just add it to virsh.

Don't know ... I've been thinking about this on and off for a while, and 
I can't see a good way to fix it.

Rich.

-- 
Emerging Technologies, Red Hat  http://et.redhat.com/~rjones/
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