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

On 30/05/13 15:32, George Dunlap wrote:
On Tue, May 14, 2013 at 2:11 PM, Diana Crisan <dcrisan@xxxxxxxxxxxx> 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 

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?
Sorry for the misunderstanding.
The host is 3.5.0-23-generic and the guest is 3.2.0-39-virtual

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