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Date: Mon, 28 Mar 2011 18:32:17 +0200
From: Jes Sorensen <Jes.Sorensen@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Relative/Absolute timing snapshot problem
References: <201103181339.33709.ck@iseclab.org> <4D906F99.9080808@redhat.com>
	<201103280925.57531.ck@iseclab.org>
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To: Clemens Kolbitsch <ck@iseclab.org>
Cc: qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>

On 03/28/11 18:25, Clemens Kolbitsch wrote:
>> Hi Clemens,
>> > 
>> > Could you clarify what you are doing, when you say snapshot do you mean
>> > a savevm operation (ie. checkpoint) or a disk snapshot?
> I Jes,
> 
> sorry for not being clear: I use a savevm operation.
> 
> Following setup: I have a base file (qcow2 or qew format) and a snapshot file 
> (generated via 'qemu-img create -b <basefile> -f qcow2 <snapshotfile>') and 
> boot the snapshot file. Once the system (WinXP SP3 guest) has fully started, I 
> create a snapshot (savevm <foo>) and exit the emulator. Later, I resume the 
> snapshot by starting Qemu with the snapshotfile and say 'loadvm <foo>'.
> 
> Actually, I found that the times I gave in my last email were way 
> underestimated. The time difference is MUCH larger than 2-3 seconds per day. A 
> week-old snapshot can take minutes to load on a reasonably idle host machine.

Ok, then I am pretty much in the dark on this one - I don't know
anything about the checkpoint/restart feature and the impact on things
like the clock. I only worked on the live snapshot code (for disk
snapshots).

Hopefully someone else will have an idea.

Cheers,
Jes