Patch management: testing monthly software updates

Software Patch Management is the process used by almost every modern company that cares about the security of its own IT infrastructure.

Updates or patches are an additional software tool that is used to correct defects found in the software or change its functionality.

There are two types of updates:

1. for operating systems and server software, used to support an adequate level of security and eliminate security issues;
2. for application software (eg, Microsoft Office, Adobe Acrobat or client parts of business applications) that are required to solve the problems with frequently used or important libraries and other parts of source code.

The method of update management is a combination of update testing approach and updated release deployment approach.

The two most common approaches to update testing are:

1. testing on local virtual machines;
2. testing in a comprehensive test environment.

Modern technology allows testing updates by means of virtualization without involving additional equipment. The most commonly used and affordable products to create virtual machines and networks are: VMware or Oracle VirtualBox. Typically, virtualization technology is used for small networks with 45-70 workstations.

The change management process can also be simplified by using only a couple of corporate computers or the so-called test clients. By installing the necessary updates on such clients and testing the system after installation you can see the impact of changes and see the result of update installation with a minimal impact on your real IT infrastructure. Testing using a comprehensive test environment is applicable for large enterprise networks and ensures high-precision testing. In this case the approaches to update installation and tools for update management are the same as in an industrial environment.

Patch Management stages:

1. Preparation of test clients
2. Creation of update sheets
3. Deployment in a test environment (LAB Deployment)
4. Deployment with pilot users (PRE Deployment)
5. Deployment of tested updates in a production IT environment (PRO Deployment).

Find out more details about all testing stages and steps in our post on Habrahabr.