A Case Study of Server Virtualisation (virtualization)

Server Virtualisation is getting a lot of press, but like most new technologies, this 'IT gibberish' takes some translation for business owners to see the benefits.

IT Leaders recently completed virutalisation of its head office server rack, giving an easy to understand case study for you.

What is Virtualisation and why is it good?

Traditionally a business will run a different server for every one or two server roles.  For example, a typical situation for a smaller SME would be to have one server running Microsoft Small Business Server, which gives the business file & print sharing, an email server, and domain controller.

To this base they would then add another server for new roles. If they start running a database, this would be put on a new physical server.  If they have staff logging in remotely to work, then a new physical server would be used for staff to log into.

There are good reasons to run different servers, such as:

• The speed of each IT business service can operate and be monitored independently - a speed issue in one service is isolated to that service only.
   
• Some softwares don't play nicely together on the one Windows installation
   
• Some softwares will (by design) hog a lot of memory or processor, which can slow down other activities on the server
   
• If one application or server role fails, it can be worked on and repaired without having to bring down other critical business facilities. (For example, if the database server has a problem it can be worked on without interrupting email, file access, internet access, etc etc

The thing about running lots of physical servers however, is that the more you have, the more they cost to buy (capital cost), run (electricity & cooling), and maintain (maintenance and repairs).

With virtualisation, you can have multiple server environments running on a single physical server. In other words, you can have 3,4,5 or more installations of Windows server, running on the same server box.  Each installation works independently, but all share the one set of hardware.

This reduces capital costs, running costs and maintenance costs.
 

Case Study: Turning Six Servers into One

Before Virtualisation

Here are the physical servers we had when the project began:

1. Domain Controller and Email Server and File/Print Share
2. Terminal Server and File Share
3. Sharepoint Server
4. WSUS Server (controls software updates for our clients)
5. Performance Monitoring Server (monitors every computer device on all our clients networks)
6. Reporting Server (generates performance reports from the monitoring)

In addition we wanted to set up two additional servers:

7. Data Centre monitoring (dedicated server for our new data centre facilities)
8. Backup Server (to offer our clients a backup service which runs over night across the internet, storing their data on our server.)

Our power usage for the server rack was approximately 3500 VA, and would have gone over 4500 VA by adding two more servers.  

Adding more servers was also going to require more cooling, further increasing capital and running costs.

TIme to maintain 8 servers properly would normally be in the realm of 20-30 hours per month.

Considerations during virtualisation

So we went down the virtualisation path for our own equipment and were interested in experimenting with the boundaries of how many virtual servers will run effectively and safely on a reasonably priced single physical server.  Bear in mind that we have less than 20 staff at this point, so there is minimal load on several of the servers, a situation that will be different for each business. 

Not all servers are good to virtualise.  Our Performance Monitoring server does currently need its own physical server.  We also decided to leave the number one server as it was, which minimised the operational impact of the project.  Both of these servers are less than 12 months old and good quality Hewlett Packard hardware so we were already happy with them from those angles.  That left servers 2,3,4,6,7 and 8 as candidates for virtualisation.

This required purchasing one new server with two dual-core processors, good hard drive speed, and plenty of drive space.  We started off with 3.5TB of drive space and 12 GB of RAM, with room to increase if required.

Using Microsoft Server 2008 Hyper-V (VM Ware is another good option), we then installed the host operating system and six other operating systems.  We were able to cut each server over independently, resulting in a seamless transition. After each new server was brought on line we monitored server software performance and hardware utilisation.  With virtualisation you want to maximise the utilisation of your server hardware, but not overload the hardware. It is incredibly flexible and allows you to assign hardware resources dynamically.  For example, we could allocate to one Windows server environment, 2GB of RAM (out of the 12GB installed), 50GB of drive space and one 'virtual processor'. Then we monitor performance of the server and then tweak up or down accordingly.  Allocating another 1GB of RAM is just a five minute tweak.   

You also need to be aware that the more roles that one set of physical hardware is performing, the more important it is that this hardware is reliable and the downsides of hardware failure are catered for. You will definitely want fast-response warranties (eg 2hr onsite response form the hardware vendor). You also may wish to have new spare components on hand for immediate swap out, since a 2hr warranty response does not guarantee that specific parts are not requried that will take a week or more to arrive. In our case we will have a spare motherboard on hand as it will be slow to procure that model, and employ the extra protection of image-based backups that can be restored to any hardware.

After Virtualisation

Number of Physical Servers: 3

Number of Operating System environments: 8

Approximate power usage: 1800VA

Time to maintain: Around 11 hours per month.

So in analysis we have better than halved our direct power usage, halved our maintenance costs, and removed the need to upgrade cooling.

Our equipment at our data centre in Varsity Lakes, is designed from the ground up for virtualisation.  Using latest generation Hewlett Packard 'blade' technology, we can run hundreds of virtual environments on industrial-strength servers, with a range of redundancy options such as complete automated fail-over in the event of hardware failure.

Talk to IT Leaders today about whether virtualisation can improve your business.