Open Stack

not the video I was looking for, but he kind of makes the point about planning...
http://youtu.be/2E0C9zLSINE?t=42m55s

# Shawn Hartsock


----- Original Message -----
> From: "Shawn Hartsock" <hartsocks at vmware.com>
> To: "OpenStack Development Mailing List (not for usage questions)" <openstack-dev at lists.openstack.org>
> Sent: Tuesday, November 12, 2013 6:38:21 PM
> Subject: Re: [openstack-dev] Custom Flavor creation through Heat
> 
> 
> 
> ----- Original Message -----
> > From: "Yunhong Jiang" <yunhong.jiang at intel.com>
> > To: "OpenStack Development Mailing List (not for usage questions)"
> > <openstack-dev at lists.openstack.org>
> > Sent: Tuesday, November 12, 2013 5:39:58 PM
> > Subject: Re: [openstack-dev] Custom Flavor creation through Heat
> > > -----Original Message-----
> > > From: Shawn Hartsock [mailto:hartsocks at vmware.com]
> > > Sent: Tuesday, November 12, 2013 12:56 PM
> > > To: OpenStack Development Mailing List (not for usage questions)
> > > Subject: Re: [openstack-dev] [nova] [heat] Custom Flavor creation through
> > > Heat
> > > 
> > > My concern with proliferating custom flavors is that it might play havoc
> > > with the underlying root-case for flavors.
> > > 
> > > My understanding of flavors is that they are used to solve the resource
> > > packing problem in elastic cloud scenarios. That way you know that 256
> > > "tiny" VMs fit cleanly into your hardware layout and so do 128 "medium"
> > > VMs and 64 large VMs. If you allow "flavor of the week" then the packing
> > > problem re-asserts itself and scheduling becomes harder.
> > 
> > I'm a bit surprised that the flavor is used to resolve the packing problem.
> > I
> > thought it should be handled by scheduler, although it's a NP problem.
> 
> I should have said "flavors help to make the packing problem simpler for the
> scheduler" ... flavors do not "solve" the packing problem.
> 
> > 
> > As for custom flavor, I think at least it's against current nova
> > assumption.
> > Currently nova assume flavor should only be created by admin, who knows the
> > cloud quite well.
> > One example is, flavor may contain extra-spec, so if an extra-spec value is
> > specified in the flavor, while the corresponding scheduler filter is not
> > enabled, then the extra-spec has no effect and may cause issue.
> > 
> 
> Beyond merely extra-specs my understanding was that because you *have*
> flavors you can make assumptions about packing that make the problem space
> smaller... someone made a nice presentation showing how having restricted
> flavors made scheduling easier. I can't find it right now. It was presented
> at an OpenStack summit IIRC.
> 
>