Microsoft's Hyper-V technology, launched last week, offers every
business running Windows Server 2008 the ability to use
virtualisation out of the box without buying additional
software.
The Microsoft product will compete directly with the market
leader, VMWare ESX Server. Both are free, but are very
different platforms.
VMWare is a mature product with advanced functions such as
VMotion, which supports live migration. It allows enterprise users
to move applications from one virtual machine to another without
disruption, which is a key requirement in business continuity.
Microsoft's Hyper-V product is much less sophisticated.
Roy Illsey, senior research analyst at Butler Group, says, "It
is aimed at small and medium-sized businesses who want to
consolidate servers. Microsoft appears to be targeting users that
do not need the advanced features of VMWare."
And while VMWare works on older generations of AMD and Intel
server processors, which power many of today's PC servers in
datacentres, Hyper-V only works on the latest generation of Intel
and AMD server chips that support virtualisation, namely AMD
Virtualization (V) and Intel Virtualization Technology (VT).
Licensing
As IT departments move from small-scale virtualisation projects
to complete datacentre virtualisation, affecting hundreds or
thousands of servers, users will need to evaluate the licensing
options of each product.
Microsoft imposes restrictions on moving applications running on
Hyper-V between one physical server and another. This makes it
difficult for IT departments to move applications temporarily from
one server to another during routine maintenance.
"The administrator cannot move the operating system back for 90
days. If he does, he will no longer comply with Microsoft
licensing," says Drue Reeves, research director at Burton
Group.
For small businesses that cannot benefit from Microsoft's volume
licensing agreements, the cost of licensing
Hyper-V is high.
On the other hand, Hyper-V may help IT managers reduce their
VMWare licence fees since Hyper-V can be used instead of VMWare for
server consolidation. IT directors culd buy VMWare licences only
when they need VMotion to run features such as live migration.
A complicating factor is that businesses may find it difficult
to manage virtualisation technology from more than one supplier.
The industry is only just starting to address the
problem of how to integrate virtualisation management software
packages (known as hypervisors) from differnt suppliers. These
packages control and manage the underlying hardware.
Tony Lock, programme director at Freeform Dynamics, says major
suppliers such as IBM, CA and BMC are building the management of
hypervisors into their products, but have made little progress in
developing standards to support virtualisation management that
would work across different hypervisors.
Users who want to deploy virtualisation to improve the uptime of
their datacentre are likely to run VMWare with the live migration
features in VMotion. But users only interested in server
consolidation should consider the cut-down features offered by
Microsoft Hyper-V.
What is a hypervisor?
Also known as a virtual machine monitor, a hypervisor is the
software that controls and manages the underlying hardware. Both
VMWare's ESX and Microsoft Hyper-V include a hypervisor. Operating
systems known as "guest operating systems" such as Windows or
Linux, can be installed on top of the hypervisor and run in a
virtual machine (VM), instead of directly on a physical server.
Since the hypervisor software can manage several VMs
independently, businesses are able to consolidate applications onto
a single physical server. The hypervisor provides each application
with its own virtual machine and server operating system.