Red Hat Enterprise Virtualization 3.1 is now available, giving Red Hat (NYSE: RHT) new ammunition in its battle against VMware (NYSE: VMW) vSphere and Microsoft (NASDAQ: MSFT) Hyper-V. The bigger question: How will each vendor promote virtualization as customers increasingly explore software-defined data centers? Hmmm...

First, the facts on RHEV 3.1, which is based on an open source hypervisor called KVM (kernel-based virtual machine). Red Hat claims RHEV 3.1 now supports up to 160 logical CPUs and up to 2 terabytes of memory, per virtual machine, and updates its KVM hypervisor to support the latest industry-standard x86 processors. Red Hat says the update also offers an enhanced user interface, improved cross-platform web administration portal, updated reporting dashboard, new networking capabilities and enhanced disk storage.

RHEV is a critical piece in Red Hat's push beyond Linux to support middleware (JBoss) and Red Hat Storage. In fact, RHEV 3.1 is integrated with Red Hat Storage, an open source storage software solution for the management of data, including file and object, structured and unstructured.

Red Hat has previously predicted that RHEV virtualization technology will leapfrog VMware, much in the way that Linux has leapfrogged Unix in terms of market share. But so far that appears to be wishful thinking. Although Red Hat has a strong following among CIOs and cloud services providers, The VAR Guy hasn't heard overwhelming RHEV momentum so far.

In stark contrast, the real battle appears between Windows Server 2012 (with a new Hyper-V release) and VMware vSphere. And even that battle is shifting, as Microsoft begins to talk about software-defined networking in Windows Server, and VMware evangelizes software defined data centers, which virtualize compute, storage and networking. VMware 's vCloud Suite is the core building blog for those software defined data centers.

So where do we go from here? The obvious answer is Red Hat North America Partner Summit (January, San Diego), which is one of The VAR Guy's Top 100 Channel Partner Conferences for 2013. Perhaps there, Red Hat will further explain how RHEV will potentially chip away at VMware.