Open Stack

On 2/10/2015 4:27 AM, Daniel P. Berrange wrote:
> On Mon, Feb 09, 2015 at 05:15:26PM +0100, Andreas Maier wrote:
>>
>> Hello,
>> I would like to ask for the following feature freeze exceptions in Nova.
>>
>> The patch sets below are all part of this blueprint:
>> https://review.openstack.org/#/q/status:open+project:openstack/nova
>> +branch:master+topic:bp/libvirt-kvm-systemz,n,z
>> and affect only the kvm/libvirt driver of Nova.
>>
>> The decision for merging these patch sets by exception can be made one by
>> one; they are independent of each other.
>>
>> 1. https://review.openstack.org/149242 - FCP support
>>
>>     Title: libvirt: Adjust Nova to support FCP on System z systems
>>
>>     What it does: This patch set enables FCP support for KVM on System z.
>>
>>     Impact if we don't get this: FCP attached storage does not work for KVM
>>     on System z.
>>
>>     Why we need it: We really depend on this particular patch set, because
>>     FCP is our most important storage attachment.
>>
>>     Additional notes: The code in the libvirt driver that is updated by this
>>     patch set is consistent with corresponding code in the Cinder driver,
>>     and it has seen review by the Cinder team.
>>
>> 2. https://review.openstack.org/150505 - Console support
>>
>>     Title: libvirt: Enable serial_console feature for system z
>>
>>     What it does: This patch set enables the backing support in Nova for the
>>     interactive console in Horizon.
>>
>>     Impact if we don't get this: Console in Horizon does not work. The
>>     mitigation for a user would be to use the Log in Horizon (i.e. with
>>     serial_console disabled), or the "virsh console" command in an ssh
>>     session to the host Linux.
>>
>>     Why we need it: We'd like to have console support. Also, because the
>>     Nova support for the Log in Horizon has been merged in an earlier patch
>>     set as part of this blueprint, this remaining patch set makes the
>>     console/log support consistent for KVM on System z Linux.
>>
>> 3. https://review.openstack.org/150497 - ISO/CDROM support
>>
>>     Title: libvirt: Set SCSI as the default cdrom bus on System z
>>
>>     What it does: This patch set enables that cdrom drives can be attached
>>     to an instance on KVM on System z. This is needed for example for
>>     cloud-init config files, but also for simply attaching ISO images to
>>     instances. The technical reason for this change is that the "IDE"
>>     attachment is not available on System z, and we need "SCSI" (just like
>>     Power Linux).
>>
>>     Impact if we don't get this:
>>        - Cloud-init config files cannot be on a cdrom drive. A mitigation
>>           for a user would be to have such config files on a cloud-init
>>           server.
>>        - ISO images cannot be attached to instances. There is no mitigation.
>>
>>     Why we need it: We would like to avoid having to restrict cloud-init
>>     configuration to just using cloud-init servers. We would like to be able
>>     to support ISO images.
>>
>>     Additional notes: This patch is a one line change (it simply extends
>>     what is already done in a platform specific case for the Power platform,
>>     to be also used for System z).
>
> I will happily sponsor exception on patches 2 & 3, since they are pretty
> trivial & easily understood.
>
>
> I will tenatively sponsor patch 1, if other reviewers feel able to do a
> strong review of the SCSI stuff, since this is SCSI host setup is not
> something I'm particularly familiar with.
>
> Regards,
> Daniel
>

2 of the 3 changes have been merged outside of the FFE process, the only 
remaining one is the FCP support:

https://review.openstack.org/#/c/149242/

The question is what is the impact to s390x users without this?  Does 
this make using cinder impossible for zKVM users?

-- 

Thanks,

Matt Riedemann