libvirt users - Nov 2017 - Re: kvm/libvirt on CentOS7 w/Windows 10 Pro guest

Tony Brian Albers writes:
> On 11/27/2017 05:28 PM, Benjammin2068 wrote:
> > Thanks for the reply.
> >
> > IIRC, I've even rebooted the system (host as well) with no
success... but
> maybe not. I'll try your suggestions again if I have an issue.
> >
> > I really thought it was updates. I also don't use any VirtIO stuff
either.
> As plain and stock a setup as I can get.
> >
> > Hopefully this glitch gets fixed soon. What a way to freak admins out.
:P
> >
> > Thanks,
> >
> >   -Ben
> >
> >
> Hmm.. could this somehow be related to the fast startup thing in win10?
> I mean, if fast startup is disabled, will that help?
>
> Just a thought.
Fast startup does not get utilized for reboots, only for regular shutdowns.  
The actual option in Windows settings reads:

"This helps starts your PC faster after shutdown. Restart isn't
affected."

On 11/28/2017 12:53 PM, Sam Varshavchik wrote:
> Tony Brian Albers writes:
> 
>> On 11/27/2017 05:28 PM, Benjammin2068 wrote:
> 
>> > Thanks for the reply.
>> >
>> > IIRC, I've even rebooted the system (host as well) with no 
>> success... but maybe not. I'll try your suggestions again if I have
an
>> issue.
>> >
>> > I really thought it was updates. I also don't use any VirtIO
stuff
>> either. As plain and stock a setup as I can get.
>> >
>> > Hopefully this glitch gets fixed soon. What a way to freak admins 
>> out. :P
>> >
>> > Thanks,
>> >
>> >   -Ben
>> >
>> >
>> Hmm.. could this somehow be related to the fast startup thing in win10?
>> I mean, if fast startup is disabled, will that help?
>>
>> Just a thought.
> 
> Fast startup does not get utilized for reboots, only for regular 
> shutdowns. The actual option in Windows settings reads:
> 
> "This helps starts your PC faster after shutdown. Restart isn't
affected."
> 
Thanks, I wasn't sure about that.
So a restart/reboot is closer to a cold-start than a shutdown and 
power-up is. Makes sense....

Yeah, I know there's a way to disable fast-start end also to avoid it 
when shutting down.

So restart avoids the hibernation-thing that fast start uses, but does 
it do so to full extent? If it saves just the least bit of info, that 
could be the reason for the boot issue. Just me thinking.. I haven't 
really used windows for the last 17 yrs.

/tony

-- 
Tony Albers
Systems administrator, IT-development
Royal Danish Library, Victor Albecks Vej 1, 8000 Aarhus C, Denmark.
Tel: +45 2566 2383 / +45 8946 2316

Tony Brian Albers writes:
> >> Hmm.. could this somehow be related to the fast startup thing in
win10?
> >> I mean, if fast startup is disabled, will that help?
> >>
> >> Just a thought.
> >
> > Fast startup does not get utilized for reboots, only for regular
> > shutdowns. The actual option in Windows settings reads:
> >
> > "This helps starts your PC faster after shutdown. Restart
isn't affected."
> >
>
> Thanks, I wasn't sure about that.
> So a restart/reboot is closer to a cold-start than a shutdown and
> power-up is. Makes sense....
>
> Yeah, I know there's a way to disable fast-start end also to avoid it
> when shutting down.
>
> So restart avoids the hibernation-thing that fast start uses, but does
> it do so to full extent? If it saves just the least bit of info, that
> could be the reason for the boot issue.
It's also entirely possible that "Restart isn't affected" part
refers only
to restarts that get initiated after applying system updates, so a manually- 
initiated restart still hibernates, despite this claim otherwise.
>  Just me thinking.. I haven't
> really used windows for the last 17 yrs.
Well, some Googling around found the instructions for disabling fast start  
up in Windows 10.

Then, I took a Windows 10 guest that I successfully nursed through the fall  
creator's update by manually starting it for every reboot. The host was also
updated to Fedora 27 and qemu 2.10 during the same timeframe.

I reenabled the reboots in domain XML file, and disabled fast startup in  
Windows 10. So far, I've succesfully rebooted that VM twice without any  
issues. I'll probably need to reboot it 3-4 times more, before cautiously  
marking this as a solved issue; but not quite sure whether the deciding  
factor is the fall creator's update, qemu 2.10, or disabling fast startup.

I have not noticed any marked difference in the actual startup speed. If  
anything, Windows seems to boot a bit faster, and the CPU utilization seems  
to settle down pretty quickly, after a reboot. Which kind of makes sense,  
actually, now that I'm aware of the fast startup "feature", and I
find it
absolutely hillarious.

See: if Windows was really hibernating, then after it boots up the dumb  
thing obviously wants to immediately kick off every frigging last scheduled  
task it has, since it probably came due during the time the whole bloody  
thing was off. I always had a laugh looking at virt-manager showing the  
guest pegging the CPU at 100% for 10-30 minutes after I start up the VM.  
That's Windows for you. Well, now, with the fast startup disabled, the  
virtual CPU settles down pretty quickly.

Also the system startup audio chime reliably plays every time now, too. I  
guess waking up from hibernation doesn't merit the audio chime.