The Goals of Tape Backup

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Backup Seems Simple …

Conceptually, a backup strategy is simple. A system administrator decides what data is critical for business operation, determines a backup schedule that has a minimal effect on operations, and uses a backup utility program to make the copies. The backups are stored in a safe place so they can be used to recover from a failure.

Though a backup strategy is quite simple in concept, the difficulty comes in the details. Architecting a backup and recovery strategy is more involved than most people realize. One of the most frustrating and discouraging tasks is determining where to start. What at first seems a simple task becomes daunting as you start digging deeper and realize how many elements of the backup strategy are interconnected. For example, as a system administrator of a large enterprise, chances are you would not want the burden of deciding what data is backed up when, and for how long it is kept. In fact, you may be presented with various analysis summaries of the business units or own the task of interviewing the business unit managers yourself in order to have them determine the data, the window in which backup may run, and the retention level of the data once it is stored on the backup media. This is often called a business impact analysis (BIA) and should yield some results that will be useful during the policy-making process. The results of these reports should also help define the recovery window, should this particular business unit suffer a disaster where data cannot be accessed or updated. Knowledge of these requirements may, in fact, change the entire budget structure for your backup environment, so it is imperative during the design and architecture phase that you have some understanding of what the business goals are with regard to recovery.

You will find that most business unit managers are not as concerned about backup as they are with recovery. As you can see from the level of complexity of our example, too often the resulting frustration may lead to inactivity where nothing gets done-or at least not done in the most effective manner. The obvious intent of a backup and recovery system is to provide data protection. Since we are setting up a system to protect the data, the next step also seems obvious: Determine how much data is in the enterprise and where it resides. This is an important part of establishing the backup and recovery system, but it does not provide enough information to architect a strategy. In addition to knowing how much data you have and where it is, you must also have a good understanding of why the data is being backed up and what the recovery requirements are. This is necessary so you can make the appropriate decisions about the overall backup and recovery strategy. The more you understand the nature of the data and the level of protection required, the better decisions you can make in setting up the entire backup and recovery environment.

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