If you’ve been wondering what the real differences are between VMware and other architectures and how that difference translates into benefits, read on. (For a slightly deeper dive, check out this 13-page white paper: VMware Infrastructure Architecture Overview.)

Link: VMware: Virtual Reality: A Look at Some VMware Infrastructure Architectural Advantages.

Our customers have been asking us for an explanation of the key
differences between the VMware ESX hypervisor architecture and the
Windows-based Hyper-V architecture they’ve been hearing about recently
from Microsoft.  We put together this summary explaining the elements
of the ESX architecture that we believe set it apart from Hyper-V and
Xen and the reasons behind some of our design decisions.  We thought it
would be interesting material for the readers of this blog, so take a
look and tell us what you think…

Complete Virtual Infrastructure


VMware ESXi – The Most Advanced Hypervisor

VMware ESXi 3.5
is the latest generation of the bare-metal x86 hypervisor that VMware
pioneered and introduced over seven years ago. The industry’s thinnest
hypervisor, ESXi is built on the same technology as VMware ESX,
so it is powerful enough to run even the most resource-intensive
applications; however, it is only 32 MB in size and runs independently
of a general-purpose OS.

The following table shows just how much smaller the VMware EXSi
installed footprint is compared to other hypervisors. These are results
from installing each product and measuring disk space consumed, less
memory swap files.

Comparative Hypervisor Sizes (including management OS)

VMware ESX 3.5 2GB
VMware ESXi 32MB
Microsoft Hyper-V with Windows Server 2008 10GB
Microsoft Hyper-V with Windows Server Core 2.6GB
Citrix XenServer v4 1.8GB

As the numbers show, ESXi has a far smaller footprint than competing
hypervisors from vendors that like to label ESX as "monolithic."

The ESXi architecture contrasts sharply with the designs of
Microsoft Hyper-V and Xen, which both rely on a general-purpose
management OS – Windows Server 2008 for Hyper-V and Linux for Xen –
that handles all management and I/O for the virtual machines.

Indirect_arch        Indirect_arch   

The VMware ESX direct driver architecture avoids reliance on a heavyweight Windows or Linux management partition OS.

Read the whole thing, as they say…