Hyper-V

Hyper-V Overview

Virtualisation was once found almost exclusively in large data centres. These days it can be found in many small to medium size businesses, thanks in part to powerful lower end servers and the advent of “free” virtualisation software.

Server Virtualisation comes in two main forms:

  • Host based virtual machines that run on top of an existing operating system e.g. VMware workstation, Microsoft Virtual PC, Sun VirtualBox and Parallels Desktop.
  • Hypervisor systems where the Virtualisation layer sits directly on top of the physical hardware and doesn’t require a host operating system. e.g. Microsoft Hyper-V Server, VMware ESX and Citrix XenServer.

Hyper-V Server 2008 is available as a free download and is essentially a modified version of Windows 2008 Server Core without the ability to add roles other than Hyper-V. The user interface is PowerShell command line only i.e. no GUI. A remote management console can be used to configure the Hyper-V environment or for larger environments you have the choice of either  System Centre Virtual Machine Manager (SCVMM) or Citrix Essentials for Hyper-V.

System Requirements:

  • x64 Based Intel (with VT extensions) or AMD (with AMD-V extensions) CPU
  • Data Execution Prevention must be enabled in hardware
  • 2GB RAM plus RAM for each guest Operating System
  • Either Hyper-V Server or a copy of Windows 2008 Standard, Enterprise or Datacentre

Note that you shouldn’t automatically assume all server hardware will support Hyper-V. In some cases it may be necessary to update firmware or install hardware vendor supplied updates.

Hyper-V systems can host a number of different operating systems include:

  • Windows 2003 and 2008 Server 32bit and 64bit Editions
  • Windows Vista SP1
  • Windows XP SP2 or later
  • SuSE Enterprise Linux (other versions of Linux may work but are not supported)

Limitations:

Hyper-V is currently in its first release and as such has a number of limitations when compared to VMWare ESX. Limited support for hardware pass through e.g. SCSI tape devices can’t be accessed from Hyper-V hosts but some USB devices can. Hyper-V doesn’t currently have a VMotion type function used in high-availability systems.┬áMany of these features are enterprise type functions and may not be needed in small to medium size networks and given the cost of getting those features these limitations are accepted by many people.

Some applications may not be supported in a virtual environment and this should be taken into consideration when designing a solution. Applications that require high disk I/O are often in this category, this doesn’t mean they won’t work but you may not get the level of performance you would expect.

Watch this space:

Windows 2008R2 is due for release on the 22nd of October 2009 and will feature many improvements to Hyper-V. One of the key new features is Live Migration which provides VMotion type functionality and will help narrow the feature gap. Hyper-V is a hot technology and a key part of Microsoft’s network strategy and as such I am sure we will continue to see rapid improvement in functionality in the future.

Hyper-V Home Page
Hyper-V Team Blog

EBS 2008 Premium Server Overview

The premium edition of Essential Business Server 2008 (EBS) includes an additional Windows 2008 Standard Server licence and SQL 2008 standard license. While the three servers that make up the core of EBS are 64bit, the forth server can be either 32bit or 64bit. Here are a few ways this server can be used to enhance the network environment.

Virtualisation

With the included Windows 2008 Standard server license you get rights to run a single Virtual Instance of Windows 2008 Standard. The physical server can be installed as a Hyper-V host for a virtual server running a second instance of Windows. Additional Windows licenses can be purchased to run additional virtual machines.

SQL

SQL 2008 Standard Edition is a powerful database management system that can be used to host a wide range of SQL applications e.g. Microsoft Dynamics, Sharepoint content databases, SAP etc. It also features reporting, data analysis and replication technology and is a great platform for managing data company wide and making that data accessible.

SQL 2008 Home Page

Compatibility

In some environments it might be desirable to have a 32bit Windows server e.g. to support legacy 32bit only applications or devices such as printers that don’t have a suitable 64bit driver. Either a 32bit physical operating system or a 64bit instance running Hyper-V with a 32bit virtual machine can be useful options to get around these issues.

Client Access Licenses

When adding new users to EBS 2008 via the EBS Management Console you can choose between standard and premium client access licenses. If you have users who don’t require access to the forth server you can assign a standard CAL to those users.

EBS 2008 Edition Comparision