Martin’s Weblog

Why I like Virtual Servers

The “solutions” from the IT industry over the last decade haven’t appealed to me a great deal. I have found clustering and storage area networks (SAN) too complex – complexity can interfere with fast recovery and support.  Blade servers offered little that was new – just packed server functions into a smaller and smaller space.

Virtual servers however offer something new and actually useful to computer users – no wonder IT people and the IT industry are raving about them.

In a sense operating systems like Linux and Windows provide virtual machines for applications. Applications  like Word or Exchange for instance  talk to the operating system rather than the hardware directly. The trouble is that applications these days bind quite tightly into the operating system and the operating system-application become like a kind of super package. Virtual machines provide a way of dealing with the operating system-application super package and let us treat it as if the whole lot were itself an application – see  the Microsoft’s VHD catalogue for example.

I have been experimenting with the  Microsoft Virtual Server 2005 R2 SP1 – this lets you get started on a familiar platform, is free and is really easy to use. I am planning a move to virtual servers for most of our application servers (e.g. finance, personnel, on-line testing), development servers, moderate use web servers and helpdesk systems. In fact I don’t see why all servers apart from really busy (email back ends) and really big (multimedia and file) shouldn’t be moved to virtual. I will be moving to virtual as fast as I am able and can anticipate replacing about 30 servers with about 5 or 6 virtual server hosts.

System Centre Virtual Machine Manager 2007 (SCVMM) – promises the amazing option of converting a real server to virtual by “pointing” a management screen at the real server – this will do wonders for moving all those difficult application servers where the only way to move them is to re-install the application on the target machine. I had tried the beta version of this in July but couldn’t get it working so look forward to another go with the “gold code”.

Also check out the amazing new way of evaluating new systems at Microsoft’s VHD catalogue. Instead of downloading an application and then installing it you can instead  download a packaged environment  as a virtual machine – an operating systems and application all configured for you – this is how I trialled the SCVMM. The only downside of this is that the virtual machine is a multi-Gb download but with the Microsoft download agent this only took 30 minutes on our college internet connection.

From the point of view of an IT manager this is why I like virtual servers 

They save space  

I am planning to run from 4 to 8 virtual servers per host server – that saves the space of 7 servers

They save power

Each server uses two loads of electricity – one load to run it and one load for the air conditioning units to cool it. Instead powering 8 servers I can now power one host server – saving the college money and saving the environment at the same time. The space saving also makes the cooling more efficient – another saving.

They offer new options for business continuity

Even with the relatively simple Microsoft Virtual Server  a virtual server “image” (.vhd and .vmc files) can be stored on a standby host server and turned on in minutes if need be in a very simple operation. This is great for the multitude of application servers which don’t change and hold little data.

They offer new options for systems development

Instead of installing a new feature, messing up a server and then having to spend hours re-installing the whole server again with a virtual server you can just copy back the “image” and start again in about 15 minutes or discard state changes and carry on as if nothing happened.

They offer new options for business agility

New servers can be set up and tested in minutes rather than hours


October 2, 2007 Posted by | ICT, virtualsation | Leave a comment