Hi, I'm fairly new to this list, actually this is my first email sent, and to OpenStack in general, but I'm not new at all to VMware so I'll try to give you my point of view about possible use case here.
Jay you are saying that by using Nova to manage ESXi hosts we don't need vCenter because they basically overlap in their capabilities. I agree with you to some extent, Nova may have similar capabilities as vCenter Server but as you know OpenStack as a full cloud solution adds a lot more features that vCenter lacks, like multitenancy just to name one. Also in any vSphere environment managing ESXi hosts individually, this is without vCenter, is completely out of the question. vCenter is the enabler of many vSphere features. And precisely that's is, IMHO, the use case of using Nova to manage vCenter to manage vSphere. Without vCenter we only have a bunch of hypervisors and none of the HA or DRS (dynamic resource balancing) capabilities that a vSphere cluster provides, this in my experience with vSphere users/customers is a no go scenario. I don't know why the decision to manage vCenter with Nova was made but based on the above I understand the reasoning. Best, --- Juan Manuel Rey @jreypo On Mon, Apr 7, 2014 at 7:20 AM, Jay Pipes <jaypi...@gmail.com> wrote: > On Sun, 2014-04-06 at 06:59 +0000, Nandavar, Divakar Padiyar wrote: > > >> Well, it seems to me that the problem is the above blueprint and the > code it introduced. This is an anti-feature IMO, and probably the best > solution would be to remove the above code and go back to having a single > >> nova-compute managing a single vCenter cluster, not multiple ones. > > > > Problem is not introduced by managing multiple clusters from single > nova-compute proxy node. > > I strongly disagree. > > > Internally this proxy driver is still presenting the "compute-node" for > each of the cluster its managing. > > In what way? > > > What we need to think about is applicability of the live migration use > case when a "cluster" is modelled as a compute. Since the "cluster" is > modelled as a compute, it is assumed that a typical use case of live-move > is taken care by the underlying "cluster" itself. With this there are > other use cases which are no-op today like host maintenance mode, live > move, setting instance affinity etc., In order to resolve this I was > thinking of > > "A way to expose operations on individual ESX Hosts like Putting host in > maintenance mode, live move, instance affinity etc., by introducing Parent > - Child compute node concept. Scheduling can be restricted to Parent > compute node and Child compute node can be used for providing more drill > down on compute and also enable additional compute operations". Any > thoughts on this? > > The fundamental problem is that hacks were put in place in order to make > Nova defer control to vCenter, when the design of Nova and vCenter are > not compatible, and we're paying the price for that right now. > > All of the operations you describe above -- putting a host in > maintenance mode, live-migration of an instance, ensuring a new instance > is launched near or not-near another instance -- depend on a fundamental > design feature in Nova: that a nova-compute worker fully controls and > manages a host that provides a place to put server instances. We have > internal driver interfaces for the *hypervisor*, not for the *manager of > hypervisors*, because, you know, that's what Nova does. > > The problem with all of the vCenter stuff is that it is trying to say to > Nova "don't worry, I got this" but unfortunately, Nova wants and needs > to manage these things, not surrender control to a different system that > handles orchestration and scheduling in its own unique way. > > If a shop really wants to use vCenter for scheduling and orchestration > of server instances, what exactly is the point of using OpenStack Nova > to begin with? What exactly is the point of trying to use OpenStack Nova > for scheduling and host operations when you've already shelled out US > $6,000 for vCenter Server and a boatload more money for ESX licensing? > > Sorry, I'm just at a loss why Nova was changed to accomodate vCenter > cluster and management concepts to begin with. I just don't understand > the use case here. > > Best, > -jay > > > > > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >
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