Unix Backup and Recovery

Developing a Disaster Recovery Plan

Devising a good disaster recovery plan is hard work. You need to build it from the ground up, and it can take months or even years to perfect. Since computer environments are changing constantly, you continually have to test your plan to make sure it still works with your changing environment.

This chapter is not meant to be a comprehensive guide to disaster recovery planning. There are books dedicated to just that topic, and before you attempt to design your own disaster recovery plan, I strongly advise you to research this topic further. This chapter gives an overview of the steps necessary to complete such a plan, as well as discusses a few details that are typically left out of other books. It provides a frame of reference upon which the rest of the book will be based.

There are essentially six steps to designing a complete disaster recovery plan. While you may work on several steps simultaneously, the order listed here is very important. Don’t jump into the design stage before understanding what level of risk your company is willing to take or what types of disasters the plan needs to address. Likewise, what good does it do to have a well-documented, well-organized disaster recovery plan based on a backup system that doesn’t work? The six steps are as follows:

1. Define (un)acceptable loss.

   Before you develop a disaster recovery plan, decide how much you will lose if you don’t. That will help you decide how much time, effort, and money to spend on a disaster/recovery plan.

2. Back up everything.

   You have to make sure that everything is backed up—including data, metadata, and the instructions you’ll need to get them back.

3. Organize everything.

   You have everything on backup volumes. But can you find the volume you need when disaster strikes? The key to being able to find your backups is organization.

4. Protect against disasters.

   Most people think about natural disasters only when creating a disaster recovery plan. There are nine other types of disasters, and you have to protect against all of them. (The 10 types of disasters are covered in Chapter 2.)

5. Document what you have done.

   You need to document your plan in such a way that anyone can follow your steps after or during a disaster.

6. Test, test, test.

   A disaster recovery plan that has not been tested is not a plan; it’s a proposal. You don’t want to be in the middle of a disaster and discover that you have forgotten some critical steps.