"You don't need to know if Red Hat Enterprise Linux (RHEL) 4 supports the Acme Raid SuperCard, only that it is supported under ESX 3i." This seems backwards to me, because it is Linux that has great hardware support: according to recent news, ESX uses Linux 2.4 to initialize the hardware before loading the vmkernel! I don't see a lot of folks clamoring to write and bugfix drivers for VMWare ESX. It is true that if a driver for VMWare is *certified* for a given platform, then that can ease the testing and certification for individual OSes and distros. But a minimalist Linux environment running KVM or Xen will do the same thing, and Linux drivers will continue to benefit from collaborative development and testing. So while virtualization may help ease the driver burden in heterogeneous environments, VMWare is at no particular advantage over KVM or Xen in the long run, they merely have a lead in guest drivers at the moment. »