By Petr McAllister
One of my customers successfully completed the VMware vSphere: Fast Track [V6] class. The customer provided a lot of positive feedback in regards to the class, and also about new functionality in vSphere 6. However, one thing was unclear: The instructor stated there is a maximum of 10 VMware solutions per vCenter. So the question was, “When we run a complex environment with multiple vCenter servers, vRealize Operations servers, vRealize Automation, vRealize Orchestrator, Site Recovery Manager and backup appliances, how can we fit all those solutions under the 10-solution limit?”
Finding the correct answer was pretty straight forward; VMware has published a document called “Configuration Maximums vSphere 6.0,” and the information is right there. The document has very specific content on exactly what my customer was asking:
“A VMware Solution is defined as a product that creates a Machine Account and one or more Solution Users (a collection of vSphere services) … At this time, only vCenter Server is defined as a fully integrated solution and counts against these maximums. Partially integrated solutions, such as vCenter Site Recovery Manager, vCloud Director, vRealize Orchestrator, vRealize Automation Center, and vRealize Operations, do not count against these defined maximums.”
It would be easy to conclude my blog post here, but the nature of my topic is a little bit different. Looking through the PSC section of the “Configuration Maximums vSphere 6.0” document can be somewhat confusing. You’ll notice different unit maximums, some of which are specified as “per vSphere Domain,” “per site,” or “per Single PSC.”
The best way to understand PSC maximums is via a diagram found in the VMware Knowledge Base (KB) article, “List of recommended topologies for VMware vSphere 6.0.x,” which is a brilliant source of information on its own.
Assume User A has access to all four vCenter servers. When User A is authenticated in the Single Sign-on domain (also known as vSphere domain), the user can:
- Log in to Site A or Site B using the same credentials
- See all four vCenter servers in the environment (because these vCenter servers are members of the same SSO domain)
- Accomplish any task on any of the vCenter servers the user has permissions on, and perform operations that involve multiple vCenter servers as inter-vCenter vMotions
Just to be clear, here is another example: If User B has access to only one vCenter server, he/she will still be able to log in—with the same credentials—to any site that is in the same SSO domain and do any operation that User B has permissions for – but only in the permitted vCenter.
Now let’s move on to the “per single PSC” definition. The PSC can be installed as embedded on the same server with other vCenter components, but in this case, the embedded PSC serves only one vCenter server. For any multi-vCenter server and/or multi-site configuration, PSC has to be installed as an external module on a separate machine in order to serve multiple vCenter servers. But the external PSC has maximums that are specified in the “vSphere 6 Configuration Maximums” document. These limits were introduced to ensure your infrastructure functions at a good performance level.
The final term to explain here is “vSphere Site,” which is partially self-explanatory, but it would help to be a little bit more specific. The KB article “VMware Platform Services Controller 6.0 FAQs” has the best definition of a vSphere 6 site:
“A site in the VMware Directory Service is a logical container in which we group Platform Services controllers within a vSphere Domain. You can name them in an intuitive way for easier implementation. Currently, the use of sites is for configuring PSC High Availability groups behind a load balancer.”
So in other words we expect the best possible connection between sites (in terms of latency and bandwidth); however, in case of connectivity issues, every site can be autonomous—for a while—serving with full functionality – with the exception of operations that require connection to another site. PSC will get synchronized when the connection is restored. You might have more questions on PSC in vSphere 6, and if you do, the KB article noted above will answer most of those questions, and reading it is certainly a good investment of your time.
Petr McAllister is a VMware Technical Account Manager based out of Vancouver, British Columbia, Canada.
