Yep, in this post Jeff Woolsey from Microsoft explains the ESX(i) Footprint argument and other "Myths" as well
Interesting Statements from his post
- I'd like to point out that VMware touts ESXi as a 32 MB hypervisor, yet the download is over 200 MB. So, are we too assume that the other 170+ MB doesn't count?
-If you really want to focus on the disk footprint that matters, the amount of software that could be directly exposed to VM attack, the Hyper-V hypervisor and virtualization stack combined is about 20 MB, ~19.4 MB for the virtualization stack and ~600k for the hypervisor.
In short, VMware has focused on our entire footprint which is made up mostly of stuff that isn't exposed to VM traffic at all or only exposed indirectly, while ignoring the part that matters most and for which VMware doesn't have a strong track record.
- VMware ESXi 3.5 patch footprint alone (3.7 GB) is 42% greater than Hyper-V Server 2008 RTM (using the 2.6 GB number VMware quoted above) and all its patches COMBINED
-Not only did VMware ESXi have a 45x greater patch footprint, but they also had the most serious virtualization security flaws.
-So much for the disk footprint argument. How can the ESXi patch footprint be so huge?
Because VMware releases a whole new ESXi image every time they release a patch. Furthermore, because VMware releases a whole new ESXi image every time they release a patch it also means that every ESXi patch requires a reboot.