I know it’s well past the GA date of the product on September 10, but I still decide to write this what’s new for the completeness of vSphere SDK FAQs.
As I always emphasize, the SDK/APIs are “view” to the product (you can think it as “model” here). Therefore to understand a SDK/APIs, it’s important to check out the product first. No exception for the new features: what’s new in vSphere decides what’s new in vSphere SDK/APIs. For that, you want to check out the What’s New in VMware vSphere 5.1 at VMware website.
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After that is done, you can read on. Just remember that some new features in product do not result in API changes, for example, the vSphere 5.1 support larger virtual machines: “Virtual machines can grow two times larger than in any previous release to support even the most advanced applications. Virtual machines can now have up to 64 virtual CPUs (vCPUs) and 1TB of virtual RAM (vRAM)” (Note: the 64 vCPUs is new to the prior 32 vCPUs in vSphere 5.0)
Here a same single integer can hold old 32 and new 64 vCPUs. You won’t see any different from APIs for these types of changes.
There are, however, changes that affect the APIs, e.g., new managed object types, new properties and new methods to existing managed object types, new data types, new enumerations, and new fault types. If you have followed my blog, you know all these happened to previous upgrades of vSphere SDKs.
From a developer perspective, you most care about the new managed object types, new methods, and new properties. The other types are around these types, for example, you may find new data types in the new properties. You can skip their details and check them out when needed.
For vSphere 5.1 in particular, there is no new managed object types. This is actually the first time since the VI 3.0 (ESX 3.0 and VirtualCenter 3.0). There are changes to existing managed object types. The following are two tables copied from vSphere API Reference:
New Managed Object Methods
New Managed Object Properties