Re: consistent LVM snapshot of domUs from dom0

[Nikola Ciprich <extmaillist@linuxbox.cz>]

Hi Mark,
that's a good news! Where can I get the code? I don't see it in 
xen-unstable yet, is it available in some other repo?
When it comes to dividing the work, I could try to finish the kernel part 
and try to glue it all together.. as soon as I can get my hands on the 
code :)
so please let me know where I can get it and I'll have a look at it ASAP
cheers and thanks!
nik

  On Fri, 4 Jan 2008, Mark Williamson wrote:

> Hi there,
>
> I've started checking code into Xenbits.  Right now all that's there is the
> proof-of-concept control tools work and a stub driver in the guest kernel
> which is able to listen for commands.
>
> The actual mechanics of FS snapshotting need to be implemented, plus UI
> features (such as actually taking arguments - and more importantly only
> returning from xm fsfreeze when guest says the freeze is actually
> complete)...
>
> If you want to have a crack at plumbing this together you'd be more than
> welcome, or I can have a go at it, or we can split it.  Any preference?  I'll
> get paid for any work I do, so I'm happy to do any amount ;-)
>
> Cheers,
> Mark
>
> On Friday 04 January 2008, Nikola Ciprich wrote:
>> On Mon, 24 Dec 2007, Mark Williamson wrote:
>> Hi Mark,
>> is there some progress regarding this subject? Still, if there is
>> something I could help with, please do not hesitate to tell me what could
>> I do...
>> Cheers
>> Nik
>>
>>> Yes, I think that's a sensible first step to take.  Later on, we could
>>> perhaps look into putting some more smarts in, e.g. doing the snapshot
>>> creation automatically in the case that an LVM volume or QCow virtual
>>> disk is already being used.
>>>
>>> I hadn't come across freeze/thaw_bdev before - I'd found a lock / unlock
>>> call for filesystem locking somewhere that looked promising but not
>>> implemented it yet.  I imagine it might boil down to a similar thing in
>>> the end.
>>>
>>> Either way, being able to freeze specific block devices could be useful
>>> for backup purposes.  There's no point freezing filesystems that are not
>>> used to store backed-up data, for instance!
>>>
>>>> Yup, agree :)
>>>> Cheers!
>>>
>>> OK, I'll try and get some code online at some point and let you know when
>>> it's available.
>
>
>
> --
> Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
> Mark: To answer a question with a question: What use is a skateboard?
> Dave: Skateboards have wheels.
> Mark: My wheel has a wheel!
>
>

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