Re: sync guest time
On Thu, Apr 30, 2020 at 2:15 PM Daniel P. Berrangé <berrange(a)redhat.com> 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/bef10f6eaa93db649c36468143ce65564...
[1] - https://github.com/libvirt/libvirt/blob/master/src/libvirt-domain.c#L11292
Regards,
Daniel
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