Open Stack

+1 to Option #2.

-- dims

On Sun, Jun 15, 2014 at 11:15 AM, Gary Kotton <gkotton at vmware.com> wrote:
> Hi,
> In the Icehouse cycle it was decided to deprecate the VMware ESX driver. The
> motivation for the decision was:
>
> The driver is not validated by Minesweeper
> It is not clear if there are actually any users of the driver
>
> Prior to jumping into the proposal we should take into account that the
> current ESX driver does not work with the following branches:
>
> Master (Juno)
> Icehouse
> Havana
>
> The above are due to VC features that were added over the course of these
> cycles.
>
> On the VC side the ESX can be added to a cluster and the running VM’s will
> continue to run. The problem is how that are tracked and maintained in the
> Nova DB.
>
> Option 1: Moving the ESX(s) into a nova managed cluster. This would require
> the nova DB entry for the instance running on the ESX to be updated to be
> running on the VC host. If the VC host restarts at point during the above
> then all of the running instances may be deleted (this is due to the fact
> that _destroy_evacuated_instances is invoked when a nova compute is started
> https://github.com/openstack/nova/blob/master/nova/compute/manager.py#L673).
> This would be disastrous for a running deployment.
>
> If we do decide to go for the above option we can perform a cold migration
> of the instances from the ESX hosts to the VC hosts. The fact that the same
> instance will be running on the ESX would require us to have a ‘noop’ for
> the migration. This can be done by configuration variables but that will be
> messy. This option would require code changes.
>
> Option 2: Provide the administrator with tools that will enable a migration
> of the running VM’s.
>
> A script that will import OpenStack VM’s into the database – the script will
> detect VM’s running on a VC and import them to the database.
> A scrip that will delete VM’s running on a specific host
>
> The admin will use these as follows:
>
> Invoke the deletion script for the ESX
> Add the ESX to a VC
> Invoke the script for importing the OpenStack VM’s into the database
> Start the nova compute with the VC driver
> Terminate all Nova computes with the ESX driver
>
> This option requires the addition of the scripts. The advantage is that it
> does not touch any of the running code and is done out of band. A variant of
> option 2 would be to have a script that updates the host for the ESX VM’s to
> the VC host.
>
> Due to the fact that the code is not being run at the moment I am in favor
> of the external scripts as it will be less disruptive and not be on a
> critical path. Any thoughts or comments?
>
> Thanks
> Gary
>
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>



-- 
Davanum Srinivas :: http://davanum.wordpress.com