SERVERS

How do I licence the Server OS ?
All virtual OSs require an allocated licence. However, different server editions provide different entitlements.

Windows 2008 Standard Server – each licence allows one physical OS plus one virtual OS.
Windows 2008 Enterprise Server – each licence allows one physical OS plus four virtual OS. The Physical OS must be Windows Enterprise but the virtual OS maybe downgraded to Windows Standard as required.
Windows 2008 Datacentre Server – one licence per physical processor allows unlimited instances of virtual OS upon the physical OS. Additionally each OS may be either Enterprise version or Standard as required.

Unlike some other vendors, Microsoft does not count cores so a dual core processor still only requires one per processor licence.

Example – a quad processor Server hosting 9 virtual OS

If all OSs are Windows Std you will require 9 licenses (one x physical OS and the first virtual OS, plus 8 x remaining virtual OS). If Windows Enterprise then 3 licenses are required (one x physical OS and first 4 virtual OS, plus two x remaining 5 virtual OS). However, if Windows Datacentre is used, then four x per processor licenses would be required

In this example the Windows Enterprise licensing would be the most cost effective, but that would not be the case if you decided to use a dual processor box, or had plans to expand the number of virtual OS being hosted on the server.

Do virtual instance entitlements for Windows Server apply when using third party software such as VMware?
Yes. Microsoft’s expanded product rights apply no matter the virtualisation technology being used. Windows 2008 Server licenses can be purchased with or without Microsoft Hypervisor entitlement.

How do the changes apply to Application Server virtualisation?
As with Windows Server there are differing rules for different products as well as for different editions of the same product.

Server plus CAL licensed products (Exchange, Project, SQL etc) - Customers must assign a licence to a physical server. Each licence provides the right to run one instance either on the physical or a virtual OS on the licensed Server. If a second instance runs on a second virtual OS then two licenses would be required.

However, SQL 2005 Enterprise specifically has the enhanced entitlement to run instances on the physical and any number of virtual OS under the one licence.

Users accessing a server licensed must have the correct CAL for the latest version of server accessed, although this no longer applies to the host server i.e. if a user accessed a Windows 2003 instance running on Windows 2008 host OS then only a 2003 CAL is required.

Per Processor licensed products (ISA, SQL) - A licence is required for each physical processor if running an instance on the physical OS plus one for each virtual processor in each virtual OS running an instance. If no instance sits on the physical OS then only the virtual OS count is required i.e. a quad processor Server may only require two per processor licenses if one instance sits on a virtual OS allocated only two virtual processors.

However, as exceptions SQL 2005 Enterprise per Processor and BizTalk 2006 Enterprise per Processor licenses allow any number of instances on the physical OS plus any number within a virtual OS provided all physical processors are licensed i.e. you do not need to licence virtual processors.

How do I licence external users utilising the virtual servers?
This can be done in either of two ways. Each individual user can be allocated a User CAL for the specific server product, or alternatively external users (non-employees) can be licensed via an External Connector licence.

The External Connector requirement is one licence required per physical Server. This allows access to unlimited virtual OS installs.