On July 14th 2015, Microsoft stopped the support of windows 2003 servers. However you will be surprised there are still many servers running on these servers. Unlike windows 2003 servers’ upgrade which is past, there will be similar upgrades which will come in the near future (next will be SQL Server 2005 which will end on April 2016).

If you are assigned on a project of upgrading windows servers, here are 3 approaches which you can follow for an upgrade.

There are 3 ways to upgrade windows, in place upgrade, side by side upgrade and swing upgrade.

In place upgrade

If your application is a 64 bit application, in place upgrade is possible. In this type of upgrade, Operating System is upgraded without impacting any other components. In short, operating system is upgraded of the running domain controller. The time taken for this upgrade is comparatively lesser and the success rate is considerably higher. From a cost perspective, except the labor cost, there are no other cost components in this approach. Risk attached to this approach is also low as if the upgrade fails it can be brought back to the earlier version.

Side by Side upgrade

You create new environments (Development, Stage, Test and Production) as per the AS-IS state and install the applications and test it. It is similar to creating a new environment set up. On the Go Live date, the new set up will be active and the old set up will be brought down. Once the new set-up is stable, the old servers are decommissioned. This is a time consuming process, new servers needs to be procured, application licensing cost. Most importantly the risk is extremely low as you the AS IS environment is not tampered.

SWING upgrade –

It is similar to a side by side upgrade; however the difference is in terms of final cutover/production deployment. In a SWING approach, the IP address and servers names are interchanged during the Go Live activities. The new servers get the IP address and the name of the existing servers. Post the upgrade, the existing servers are kept for a few weeks and decommissioned once the new servers are stable. If the upgrade is unsuccessful, revert the changes made to the IP address and server name. The application will run as before and there is no impact on the users. This is a time consuming and has a cost impact similar to a side by side upgrade.

Out of these 3 approaches, in place upgrade can be only performed for 64 bit application. SWING is the most popular form of upgrade approach and side by side upgrade being the least popular.