Before you start
Objectives: Learn what we should always have in mind when doing a server upgrade.
Prerequisites: no prerequisites.
Key terms: rollback, plan, backup, ASR, documentation
Prior to doing an upgrade of server installation, we should always have a rollback plan in the case something goes wrong. For example, if server is nonfunctional after an upgrade, we can do a rollback. We can rollback to an existing server installation during the upgrade process. However, we should always keep one thing in mind. When we log on for the first time after the upgrade, rollback is not possible any more.
If we have to do a rollback after we log on for the first time, we have to do the installation from the beginning. We have to format the current installation, install new server OS, and then restore all data and applications.
One of the most important part of the rollback plan is doing a full backup of the current server system. We have to have a complete backup of the server system and data. We can also do a full Automated System Recovery (ASR) procedure before we do an upgrade. It is recommended to do ASR in addition to full backups of our data. ASR is a free solution and is built in the Windows Server OS. If we ever need to perform full recovery, we can use ASR to quickly recover our server, data and applications to its original state. So, full backups and ASR should both be part of the rollback plan. Basically, we use ASR to backup system components and settings, and we use full backups to backup and restore our data.
In our rollback plan we should also have the product keys of the system and all applications, in case we are forced to reinstall any type of software. We should also be sure that we have our installation media for the system and other software. For example, we can create ISO images from installation CDs and DVDs, so we can create additional copies if our original gets damaged.
One last thing we should do is keep documented all things considering our server system, which can than be used in the rollback plan. In fact, the rollback plan itself should be documented. If possible, we should first test the upgrade. For example, we can test the upgrade on virtual machine. We can also test our rollback plan to ensure that we have everything covered.