Open Stack

On 05/14/2013 02:52 AM, Michael Still wrote:
> Hi.
> 
> Russell -- I was reviewing https://review.openstack.org/#/c/28950/,
> and I think I found a new bug. This code assumes that both the source
> and destination for a migration have the same value set for
> CONF.instances_path.
> 
> So... Do we think that's true? Do we assume that this value is set to
> the same value deployment wide? I can see cases where that might be
> surprising to deployers.
> 
> I think we need a policy discussion here, so I'm hoping this thread
> will help us decide.

Is there ever a case where *not* setting it to the same thing is useful?

So, let's start with this:

  We assume that the value of the instances_path configuration option
  is the same across an entire migration domain, meaning that we expect
  it to be the same for the source and destination of any migration.  In
  practice this may mean across a host aggregate, a cell, or an entire
  deployment, depending on the specifics of the deployment.

Now, poke holes in it.  Is it bad?  Why?  What code makes this
assumption now that would have to change?

In the mean time, it would be good to document this expectation in the
config.

-- 
Russell Bryant