[Engine-devel] alias in disk instead of name

[Michael Pasternak]

On 10/21/2012 04:15 PM, Simon Grinberg wrote:
> 
> 
> ----- Original Message -----
>> From: "Michael Pasternak" <mpastern at redhat.com>
>> To: "Simon Grinberg" <simon at redhat.com>
>> Cc: "engine-devel" <engine-devel at ovirt.org>
>> Sent: Sunday, October 21, 2012 3:48:46 PM
>> Subject: Re: [Engine-devel] alias in disk instead of name
>>
>> On 10/21/2012 03:36 PM, Simon Grinberg wrote:
>>>
>>> ----- Original Message -----
>>>>> From: "Michael Pasternak" <mpastern at redhat.com>
>>>>> To: "engine-devel" <engine-devel at ovirt.org>
>>>>> Sent: Sunday, October 21, 2012 12:26:46 PM
>>>>> Subject: [Engine-devel] alias in disk instead of name
>>>>>
>>>>>
>>>>> The problem we caused by using alias in disk instead of name is
>>>>> break
>>>>> of search-by-name paradigm
>>>>> in engine.search dialect, not sure why we do not want forcing
>>>>> disk
>>>>> name to be unique [1],
>>>>> but lack of "name" in disk search is does not look good in my
>>>>> view.
>>>>>
>>>>> thoughts?
>>>>>
>>>>> [1] can be easily achieved via appropriate can-do-action
>>>>> verification.
>>> Names by definition are not unique IDs,
>>
>> they do, otherwise /search wasn't effective, remember users not
>> exposed to entity id, all entities fetched by-name, so names has to
>> be unique.
> 
> Yap that is what we do with many entities, and it causes problems.
> But with disks it is multiplied  
> 
>>
>>> thus it should not be enforced.
>>> What would be the auto naming conversion to ensure uniqueness with
>>> plain text?
>>
>> not sure i follow, i'll assume you refer here to empty name, - you
>> cannot have an
>> entity with no name.
> 
> Well you create a new disk - do we want to enforce the user to provide a unique disk name/alias for every disk he creates?
> This will drive the user crazy. This is important even for user only for floating/shared disks. For any other disks user does not care if it's disk1, hd1, whatever. For these kind of disk, it's just a VM disk and the user does not care if in all VMs this is called disk 1 - so why bother him?  

from the same reason we have unique clusters/datacenters/networks/templates/etc...

>    
>>
>>> Would you change these on import/export?
>>
>> would you mind elaborating on this?
> 
> Yes, 
> 
> You are already facing a problem when importing VMs that already have the same name, now you increasing the problem for disks that have the same alias. for same name we force clone if you want to import. Why for clone just because of a disk alias (this implies collapse snapshots ATM) or even bother the user with renaming disks that he does not care about the name so he just gave disk 1, 2, 3 and so on?

i see your point, but then we leave no option for the user to locate the disk,
simply because he doesn't have unique identifier,

just imagine user A creating disk and calling it X,
then user B creating disk and calling it X, they on different
domains etc., and now both want to use disk X,

how they can figure out which one to pick?, by SD, by size? agree
this is doesn't look well..., even more than that - someone may call
this "bad design"...


-- 

Michael Pasternak
RedHat, ENG-Virtualization R&D