After having just finished up a feature on virtulization pitfalls and how to avoid them (see Virtualization Gotchas: Part 1), I had some specific questions for VMware from a very large VMware user regarding limitations in the scalability of Virtual Infrastructure 3 (VI 3). The problems occur when you start trying to manage thousands of virtual machines.

One IT executive I spoke with for the story has a few thousand Virtual Desktop Infrastructure (VDI) virtual PCs and virtual servers. The VMware management tool he uses, VirtualCenter, is limited to managing 1,000 virtual machine instances (the current version supports 1,500 according to VMware), so that company has to work with several VirtualCenter management silos. Since the VDI virtual machines are a homogenous group, he'd like to manage them as a single entity. But he can't do that, and all of the cool features available with VI 3 - VMotion, Distributed Resource Scheduler (DRS), High Availability and Consolidated Backup - won't work across silos.

Furthermore, DRS, which lets you establish pools of virtual machines on a defined set of physical servers to allow dynamic workload balancing, is limited to just 16 physical machines per DRS group.

After some back and forth, Bogomio Balkansky, director of product marketing for VI 3, acknowledged in a conversation this afternoon that VMware has some challenges in this area.

"This is one of the primary things we are working on. It’s gratifying for us that we have deployments that are that big, but now its like oh, we have to support thousands of virtual machines," he says.

VI 3 was released last June. Balkansky won't say when the next major update will come out, nor would he go on record to say that these specific limitations would be addressed. One would presume, however, that they're high on the list.

Read and comment on the original, here.