[Engine-devel] Cluster default with empty processor name with PPC64 support

[Leonardo Bianconi]

>-----Original Message-----
>From: Itamar Heim [mailto:iheim at redhat.com]
>Sent: segunda-feira, 2 de setembro de 2013 13:46
>To: Leonardo Bianconi
>Cc: Roy Golan; engine-devel at ovirt.org
>Subject: Re: [Engine-devel] Cluster default with empty processor name with PPC64 support
>
>On 09/02/2013 06:43 PM, Leonardo Bianconi wrote:
>>
>>
>>> -----Original Message-----
>>> From: Itamar Heim [mailto:iheim at redhat.com]
>>> Sent: segunda-feira, 2 de setembro de 2013 10:29
>>> To: Leonardo Bianconi
>>> Cc: Roy Golan; engine-devel at ovirt.org
>>> Subject: Re: [Engine-devel] Cluster default with empty processor name
>>> with PPC64 support
>>>
>>> On 09/02/2013 03:35 PM, Leonardo Bianconi wrote:
>>>>
>>>>
>>>>>> From: Roy Golan [mailto:rgolan at redhat.com]
>>>>>> Sent: domingo, 1 de setembro de 2013 05:07
>>>>>> To: Leonardo Bianconi
>>>>>> Cc: engine-devel at ovirt.org
>>>>>> Subject: Re: [Engine-devel] Cluster default with empty processor
>>>>>> name with PPC64 support
>>>>>>
>>>>>> On 08/30/2013 10:51 PM, Leonardo Bianconi wrote:
>>>>>> Hi everyone!
>>>>>>
>>>>>> During the development of PPC64 support in the engine, we faced
>>>>>> some UX issues regarding the default Cluster (that Cluster with
>>> empty processor name).
>>>>>>
>>>>>> Currently, oVirt engine allows the default Cluster to contain
>>>>>> empty processor name, and the administrator can add VMs and/or
>>> Templates to it. The processor name can be assigned later, editing the cluster or assigning a valid host to it.
>>>>>>
>>>>>> During the implementation of PPC64 support on the engine, the
>>>>>> field "architecture" was added to Clusters, VMs and Templates
>>> entities.
>>>>>> herdado
>>>>>> So we have the following questions regarding how the UI should behave:
>>>>>>
>>>>>> - Shall we keep allowing the administrator to assign VMs and
>>>>>> Templates to the Cluster with no processor name or assigned
>>> architecture ?
>>>>>>                -> If we have an "yes" for the question above:
>>>>>>                -- We will have to assign the architecture to the
>>>>>> Cluster based on the OS of the first assigned VM, and  the
>>>>>> processor name
>>> could be defined the same way as currently ... editing the Cluster or assigning a compatible Host to it.
>>>>>>                                -- The VM creation popup will have
>>>>>> to be able to indicate the architecture of each OS ... some OSes
>>>>>> have the same
>>> name, and it may get ambiguous since the Cluster architecture is still undefined at that point (before the first VM get already
>created).
>>>>>>
>>>>>> Thanks!
>>>>>> Regards.
>>>>>> Leonardo Bianconi
>>>>>>
>>>>> To add VMs you anyway need a running host in the cluster which means the cpu name and the architecture would be the host's.
>>>>> So we can keep the cluster attributes - "cpu name" and "arch" consistent and allow them to be empty on creation.
>>>>>
>>>>>
>>>> Hi Roy!
>>>>
>>>> There is a way to add VMs in a cluster with no hosts running. Steps to reproduce:
>>>> - Initialize the oVirt engine with a new data base
>>>> - Create a new Cluster (I will call it of newCluster) in the Data
>>>> Center Default
>>>> - Add a host in the newCluster
>>>> - Add a Storage
>>>> - Create a VM in the Cluster Default
>>>> Result: The system allows a VM in a cluster with no Hosts running in it.
>>>>
>>>> Is it a bug or a system functionality? If it's a functionality, the issue above can happen.
>>>
>>> while above can happen, is it really an interesting use case to solve?
>>> can user edit the arch field of a vm? if so, i'd just block running
>>> it on incorrect cluster (just like we block on moving it between
>>> incompatible clusters) until user fix the issue
>>
>> Yes, it's interesting solve, because we use the cluster architecture when creating VMs.
>> The user cannot edit the arch field, because there is no field for that, it is inherited from the cluster. The arch is important on
>creating VMs, because it filters the OS list and defines the VM architecture.
>> What should we do?
>>
>> Thanks!!
>>
>
>so worst case the list is not filtered while creating the VM for that corner case?
>
>thinking about this some more, with all due respect to PPC and this corner case, I'd just assume if cluster arch is not yet defined, OS list
>should be filtered as x86_64.
>or, we block creating VMs on clusters which have no arch defined (I'm specifically not saying no hosts, just in case its useful somehow)

I think both are good solutions, but looking the system behavior, I think the first solution will be weird for new users and the second has problems when upgrading the data base.
I would suggest the following behavior:

1. For new data bases: Block the admin to add VMs in the cluster with no processor name (Cluster Default), i. e. no architecture.
2. For upgraded data bases, If the cluster with no processor name (Cluster Default) has:
  2.1 - VMs: Set the cluster architecture for x86_64 and allow admin use it as x86_64.
  2.2 - no VMs: Keep the cluster with no processor name, i. e. no architecture (it will keep the same behavior of the cluster for new data base - item 1)

On the item 2.1, when setting the architecture of the cluster (Cluster Default) for x86_64, the processor name will be empty. Should we set it for the lowest x86_64 level?

What do you think?

Thanks!!