VMware is a company on a mission to retain their place as the frontrunner in the virtualization marketplace and the release of vSphere 4.1 reaffirms this commitment and moves the company further down the virtualization road. vSphere 4.1 boasts new features, massively improved scalability and, of course, some fixes. Because this is the last release for ESX – it’s all ESXi after this – I’ll be talking about items in both ESX and ESXi here and in the next part.

Features

Starting with the new features list, here’s a look at just some of what to expect from this latest release:

• Active Directory integration. Available in both ESX and ESXi, Active Directory integration allows hosts to join an Active Directory domain. Once joined, users that access the host can be authenticated against Active Directory.
• Boot from SAN for ESXi. Further decoupling the server resources from the environment, ESXi now supports booting from SAN – iSCSI, Fibre Channel and FCoE are all supported as long as all of the hardware – the SAN and the adapters – is supported by VMware.
• Memory compression. The product now includes a new memory compression feature. Designed to complement existing memory management techniques such as memory overcommit, memory compression operates on the assumption that a virtual machine and host will become RAM bound before processing resources become an issue. Compression automatically kicks in when host RAM is overcommitted. The assumption is that it’s much, much faster to expend a few processor cycles compressing and accessing existing RAM that it is to swap to disk.

Scalability & Performance

From a scalability and performance perspective, older versions of vSphere/ESX/ESXi don’t have anything on vSphere 4.1.

• While a vSphere 4.0 cluster could support more than 1,200 virtual machines spread across 32 hosts. Under vSphere 4.1, this number jumps to 3,000 virtual machines but the 32 host limit doesn’t shift. This means that vSphere 4.1 can provide a much denser (or deeper) environment but it doesn’t grow in breadth so much.
• Under vCenter 4.1, a single vCenter server can now manage up to 15,000 registered individual virtual machines (10,000 active). vSphere 4.0 allowed up to 4,500 registered virtual machines with 3,000 of those active.
• vCenter can handle up to eight simultaneous vMotion processes; vMotion now operates five times faster than it used to, as well. This provides for an even more available infrastructure that can recover more quickly.

vSphere 4.1 also includes significant network and storage I/O improvements that I will be discussing in my next blog post here.