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Re: [Xen-devel] Making snapshot of logical volumes handling HVM domUcaus

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Subject: Re: [Xen-devel] Making snapshot of logical volumes handling HVM domUcauses OOPS and instability
From: "J. Roeleveld" <joost@xxxxxxxxxxxx>
Date: Mon, 13 Sep 2010 10:35:07 +0200
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On Monday 13 September 2010 02:15:28 James Harper wrote:
> > > Another thing I notice, which might be of help to people who
> > > understand this better then I do, in my backup-script, sometimes
> step
> > > "5" fails because the domU hasn't noticed the device is attached
> > > again when I try to mount it. The domU-commands are run using
> > > SSH-connections.
> > > 
> >       That probably just has to do with variations in how long it
> takes
> > the guest kernel to poll or be notified of device changes, and how
> long
> > it takes for its udev to create the device files and whatnot.
> > Introducing some sanity checks or just a longer delay in your backup
> > script would likely get around that problem.  (I could be wrong,
> though)
> I found that too. I just put the mount in a loop, breaking out when then
> device actually appears in the DomU. It's just a timing thing and I
> don't think its relevant to the problem at hand.
> James

I agree, but I thought I'd mention it here just in case it could have been 
I am not familiar enough with all the internals to be able to determine what 
we can and can not exclude.
A comparison with a system that doesn't crash is always usefull, in my 
experience :)


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