Suspended or migrated instances may have a wrong time on restore

[Vladik Romanovsky]

When a VM is resumed from suspension and/or migrated, its clock
continues from the time of suspension, i.e. it's delayed.

Running the ntpd services on the instances would not help, as ntpd can only correct minor time difference.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/316116
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=0376da0627b022bc6aeb3e423250f9e29181f9ab
Submitter: Jenkins
Branch: master

commit 0376da0627b022bc6aeb3e423250f9e29181f9ab
Author: Vladik Romanovsky <email address hidden>
Date: Thu May 12 19:33:33 2016 -0400

    libvirt: update guest time after suspend

    When an instance is resumed from suspension or a migration, the guest's
    clock might get a large delay between the current and the suspension time.
    In some cases, NTP might not be able to resynchronize the guest time and
    will result in a skewed clock.

    In order to address the issue, this patch will try to set the guest time
    after it is resumed. This operation will require the guest agent to be
    configured and running in order to be able to run. However, this operation
    will not be disruptive.

    This code is similar to a change that has been commited to oVirt.
    https://gerrit.ovirt.org/#/c/50426

    Closes-Bug: #1593745
    Change-Id: I2732af50aab238502ccdc067f62290fd962c8c64

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 14.0.0.0b3 development milestone.