[Engine-devel] alias in disk instead of name

[Simon Grinberg]

----- 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?  
   
> 
> > 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?


 
> 
> > And so on...
> > 
> > You should treat the name as a tag/alias that if you bothered to
> > update, probably means something to you, if not then you don't
> > care anyhow and will not search by it anyhow. So it's up to the
> > user what to assign.
> 
> simon, we do not have any /name today in disk, you see it in api
> for backward compatibility, actually it's emulated over /alias,

Correct, we don't have name but alias especially because we wanted to emphasize it's not unique.
But I've thought that aliases are treated like name, thus you have all the issues and suggesting to make them unique, and I'm trying to explain what we should try to avoid from having them unique. 

I agree, it's not fun when a you have 5 floating disk sharing the exact same alias - but maybe it should be the user responsibility to decide whether he is going to allow for it or not?

> 
> and the problem is when want to search by-name, it's not included
> in backend search.
> 
> > 
> >    
> > 
> 
> 
> --
> 
> Michael Pasternak
> RedHat, ENG-Virtualization R&D
>