Virtual Iron’s Enterprise Edition V3 is a virtual machine hosting platform that couples its open source hosting foundation with tools to convert existing servers into VMs and subsequently manage them.

Virtual Iron’s roots are grounded in the same Xen paravirtualization project used in Citrix’s XenSource Enterprise and Novell’s SUSE Enterprise 10’s Xen (in fact, it OEM’s the latter one). Virtual Iron Enterprise’s own secret sauce comes in the form of tools for physical-to-virtual, virtual-to-virtual server conversion and a management system that we found does a good job of managing entire VM farms.

On the downside, the current list of compatible hardware platforms for Virtual Iron are for all practical purposes confined to a short list of top 64-bit virtual processes-enabled Intel and AMD CPUs hardware. The company does offer a 32-bit version, but we did not test it because 32-bit memory confines make 32-bit platforms essentially obsolete for hosting virtual machines.

We ran Virtual Iron on a Dell PowerEdge 1950 server with an Intel V-series dual-quad-core 1.86-GHz CPU and reasonable memory (at least 4GB).

Virtual Iron lives on a server that straddles a required, separate and isolated network segment for Pre eXecution (PxE) boot provisioning of physical hosts, and an accessible network segment to access the management functions. The Virtual Iron server acts as both PxE boot server for physical servers acting as VM hosts and the VM instances on those hosts. VM images can be stored and managed on either the host’s installed disks or on a managed storage-area network. The PxE boot process (think of it as a DHCP client boot with an executable provisioned payload) uses trivial FTP -- which uses no password authentication -- to provision all PxE requests. TFTP is notoriously insecure, but acceptable in this case since the network is required to be physically isolated.

Virtual Iron uses a modification of an OEM SUSE Enterprise Server (SLES) 10 SP1 kernel as its hypervisor hosting application (see discussion in the SLES 10 review). The hypervisor kernel (referred to as “domain0”) was installed via a PxE boot server onto the Dell server host. From there, building Virtual Iron’s guest operating system hosting architecture is a matter of installing operating systems (SUSE Linux, Windows XP or Windows 2000 or 2003 Server Editions) and the desired applications manually — or through a physical-to-virtual conversion process.