A smaller virtualization footprint reduces the attack surface for external threats and can drastically lower the number of patches required— giving you a more reliable product and a more stable datacenter. Jeff Woolsey responded to questions about disk footprint around Windows Server 2008 Hyper-V, Microsoft Hyper-V Server 2008 and VMware ESX/ESXi. Quote from VMware blog: “Microsoft attempted to follow VMware’s lead to reduce the attack surface of its virtualization platform by offering Windows Server Core (a subset of Windows Server 2008) as an alternative parent partition to a full Windows Server 2008 install. However, the disk footprint of Server Core in its virtualization role’s still approximately 2.6 gigabytes (GB). Until Microsoft changes its virtualization architecture to remove its dependency on Windows, it’ll remain large and vulnerable to Windows patches, updates, and security breaches. All of the proprietary Xen-based offerings, such as those from Citrix, Oracle, Red Hat, Novell, Virtual Iron, etc., face similar issues by relying upon general purpose Linux as a core part of their virtualization architectures.” Yes, Hyper-V has a larger footprint on disk than VMware’s ESXi, but does that make it any less secure, any less patched, any less reliable, any less performant, or any less robust?
Full Article: Virtualization blog