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Re: [Xen-users] Block level domU backup

To: "Javier Guerra" <javier@xxxxxxxxxxx>
Subject: Re: [Xen-users] Block level domU backup
From: "Agent Rooker" <agentrooker@xxxxxxxxx>
Date: Tue, 28 Oct 2008 15:57:38 -0500
Cc: Nick Anderson <nick@xxxxxxxxxxxx>, xen-users@xxxxxxxxxxxxxxxxxxx, John Madden <jmadden@xxxxxxxxxxx>
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On Tue, Oct 28, 2008 at 3:54 PM, Javier Guerra <javier@xxxxxxxxxxx> wrote:
> On Tue, Oct 28, 2008 at 3:44 PM, John Madden <jmadden@xxxxxxxxxxx> wrote:
>>> the point of pausing the DomU is to get hold of a snapshot of memory
>>> state, as well as the block device(s).  when restoring, the DomU would
>>> return to the 'same' moment it was when paused.  both the disk and CPU
>>> would get back in time.
>>
>> ...And?  ...If his backup of domU happens while paused, he's still got an
>> incomplete filesystem.
>
> the 'missing' parts are in the RAM backup.
>
>
> --
> Javier
>

That's right.  As far as I can tell, the only thing the domU would
notice is that the system clock jumps forward suddenly, and all the
network connections suddenly drop.  I'm having trouble understanding
John's worries about the filesystem integrity.  It's true, it would be
a problem if I just did 'xm create' on the block device, but I'm
planning on doing 'xm restore', which should sidestep this problem.

-- 
Agent Rooker

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