Virtualization shoot-out: Red Hat Enterprise Virtualization

Red Hat's server virtualization solution mixes ease and scalability with a few odd limitations

Senior Contributing Editor, InfoWorld |

Red Hat's server virtualization solution derives from the company's 2008 acquisition of Qumranet, a small company that had been building a desktop virtualization solution based on KVM (Kernel-based Virtual Machine) technology. Unlike the hypervisors of VMware, Microsoft, and Citrix, Red Hat's virtualization does not rely solely on emulated hardware but uses paravirtualization wherever possible to map virtual machines directly to hardware via the /dev/kvmkernel interface.

While the original goal of Qumranet was desktop virtualization, Red Hat has moved the solution into the server virtualization space, supporting RHEL and Windows Server VMs, as well as Windows and Linux virtual desktops. Red Hat Enterprise Virtualization (RHEV) boasts an easy install, good performance, and strong management capabilities, with features -- including automated load balancing and high availability -- to support larger environments. It also has some quirks.

RHEV installation
Red Hat's KVM-based hypervisor installs quickly and easily. Though you can run KVM from a full RHEL installation, we installed the bare-metal RHEV Hypervisor, which is essentially an RHEL 5.6 build with only the packages necessary to support KVM. The installation went exceedingly fast on each host, requiring a scant few configuration parameters fed through the CLI host console. These included basic management network setup, password modifications, and later, the IP address of the management server.

Here's where the Qumranet acquisition sticks out: The management server, RHEV Manager, is a Windows application written in .Net that runs on Windows Server 2008 R2 and requires Internet Explorer -- not what you'd expect from Red Hat. However, a rewrite that runs on Windows and RHEL is apparently in the works.

The installation of RHEV Manager is straightforward, requiring only a few mouse clicks and the usual progress-bar observation. RHEV Manager uses a Microsoft SQL Express database, much like VMware, and installs a few other packages as well. Naturally, the Web server role and ASP.Net are all prerequisites on the Windows Server 2008 R2 system.

There is a chicken-and-egg situation in play, however, as you cannot build the management controller on a RHEV host without already having a management controller to perform the necessary configuration. This means that the RHEV Manager must initially run on a separate physical or virtual server to begin a ground-up implementation.