Re: HVM Migration of domU on Qemu-upstream DM causes stuck system clock with ACPI

[George Dunlap <George.Dunlap@eu.citrix.com>]

On Tue, May 14, 2013 at 2:11 PM, Diana Crisan <dcrisan@flexiant.com> wrote:
> This is problem 1 of 3 problems we are having with live migration and/or ACPI on Xen-4.3 and Xen-4.2.
>
> Any help would be appreciated.
>
> Detailed description of problem:
>
> We are using Xen-4.3-rc1 with dom0 running Ubuntu Precise and 3.5.0-23-generic kernel, and domU running Ubuntu Precise (12.04) cloud images running 3.2.0-39-virtual. We are using the xl.conf below on qemu-upstream-dm and HVM and two identical sending and receiving machines (hardware and software)
>
> When live migration is instigated between two identical hardware configurations using 'xl migrate', the migrate completes but the system clock in domU appears to be stuck when the domU resumes on the receiving side. For instance, running 'top', 'date', or 'uptime' will constantly report the same result. The clocks in dom0 were synchronized before migration using ntpdate. A modification of the clock using the date command in the migrated domU solves the problem; migrating back to the original machine works, but after a third migration the problem reappears.
>
> Sometimes the clock is not stuck on the first migrate, but the problem is reproducible after several migrations.
>
> How to replicate:
>
> 1. Take two machines with identical hardware and software, running the xen-4.3-rc1 version of Xen on Ubuntu Precise with 3.5.0-23-generic kernel.
> 2. Use the xl.conf below as a configuration file.
> 3. Create a VM using Ubuntu Precise and 3.5.0-23 generic.

Sorry, one question -- here you have 3.5.0-23, but above you say that
you're using 3.2.0-39-virtual?  What OS is the guest running?

 -George