qemu-discuss
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: sync guest time


From: Miguel Duarte de Mora Barroso
Subject: Re: sync guest time
Date: Thu, 30 Apr 2020 17:39:45 +0200

On Thu, Apr 30, 2020 at 2:15 PM Daniel P. Berrangé <address@hidden> wrote:
>
> On Thu, Apr 30, 2020 at 01:52:12PM +0200, Miguel Duarte de Mora Barroso wrote:
> > Hi,
> >
> > I'm seeing the following issue when attempting to update the guest's
> > clock on a running fc32 guest (using guest agent):
> >
> > ```
> > [root@virt-launcher-vmi-masquerade-mh2xm /]# virsh domtime 1 --pretty
> > Time: 2020-04-30 23:27:29
> > [root@virt-launcher-vmi-masquerade-mh2xm /]# virsh domtime 1 --sync
> > error: internal error: unable to execute QEMU agent command
> > 'guest-set-time': hwclock failed to set hardware clock to system time
>
> This error is ultimately coming from the QEMU guest agent inside
> your guest. It spawns "hwclock" and this is failing for some reason.
> You'll probably need to debug this inside the guest - strace the
> QEMU guest agent, see where it fails, and then file a bug against
> the distro for it.

Eventually I found out that if I make the call *without* specifying
the `libvirt.DOMAIN_TIME_SYNC` flag this works
as I intend. I've read the docs and could not understand what's the
purpose of this flag .

It reads "Re-sync domain time from domain's RTC" on [0]. It begs the
question: if I'm setting it to a fixed instant in time (which I am),
why would I want it to sync with the domain's RTC ?

Is there any obvious issue that will appear from calling
`virDomainSetTime` (defined at [1]) without the DOMAIN_TIME_SYNC flag
specified ?

I'm not sure if this (removing the DOMAIN_TIME_SYNC) is a fix, an ugly
hack, or a disaster waiting to happen.

>
> > # now, this one works.
> > [root@virt-launcher-vmi-masquerade-mh2xm /]# virsh domtime 1 --now
> >
> > [root@virt-launcher-vmi-masquerade-44v2x /]# virsh domtime 1 --pretty
> > Time: 2020-04-30 11:15:45
>
> This doesn't run hwclock as its merely reading the current time,.
>
> > Is there any workaround I could try ? Am I doing something wrong here ?
>
> I don't think you're doing anything wrong. This just looks like a guest
> OS bug to me.

Thanks for the prompt reply!

[0] - 
https://github.com/libvirt/libvirt/blob/bef10f6eaa93db649c36468143ce6556444a2e25/include/libvirt/libvirt-domain.h#L4712
[1] - https://github.com/libvirt/libvirt/blob/master/src/libvirt-domain.c#L11292




>
> Regards,
> Daniel
> --
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|
>




reply via email to

[Prev in Thread] Current Thread [Next in Thread]