How often should you create a backup of your business data?
The effects of a loss of service to a business can be devastating, particularly for those businesses that are fully online ones. The very fact of being off-line for them can be a life-threatening event. There is a truism in the Internet industry that says that a loss of a sale is just a click away. For a business that needs to be online 24/7/365, being unavailable to customers can be fatal.
Even for businesses that have a bricks and mortar presence, a loss of computing services can deal a severe blow to their bottom line.
The reasons for a loss of service are immaterial, but the necessity for a quick return to an operational basis is something that keeps Heads of IT awake at night. A business data backup, while necessary is not always enough.
Many forests are destroyed and electrons spent on discussing the concept of Disaster Recovery, nowadays more commonly called Business Continuity, which, simply put, is the art of starting up again as quickly as possible and as close as possible to where you were when you were stopped in your tracks. How you go about that depends on the criticality of your business systems and your budget. It also depends on the type and extent of the calamity that has put you off-line.
For a business that is truly dependent on being on-line 24/7/365, the ideal solution is a tandem system, that is, a system that is an exact duplicate of the operational system. Everything that happens on the primary system is duplicated on the secondary – a full online backup. Software and data is replicated immediately to keep the two systems in 100% step. If the primary system fails, operations immediately switch to the backup system while the primary is sorted out. A very expensive solution, but necessary if your business will fail if there is any period of extended downtime.
For the less critical business, a common part of the Business Continuity programme is to make copies of your business data at regular intervals. Again, many forests have been sacrificed to the discussion about what you need to backup and how often.
A tried and trusted system is a three-level system:
- Static Data or data that changes very infrequently is backed up once, and only again when it is changed. Systems software often falls in this category. Reinstallation takes the form of reinstalling the base package, and then applying the various patches and mods in the correct order.
- The second level are business databases. Quite often, business databases have a fairly static and a volatile component, but both need to be backed up together to ensure they stay in step. Common practice is to back them up daily.
- The third level is transaction data that is critical at key parts of a business process. In a piecework environment, details of work completed update both the production and payroll systems on a continual basis. Continuous backing up of the transaction files is essential to bringing the systems back to where they were.
To answer the question of how often to backup, the answer relates to how critical the data is. The more critical, the more often.
A second consideration in answering the question is the backup window available to make the backup copies. Some systems need to stop while the backup is taken to allow critical files to be copied, and the length of time when the systems are offline determines how long you have. That will define what backup regime you operate. It used to be common practice to take the backups when the system was closed down overnight. With the Internet, the systems may operate in many time zones, and not have an overnight in which to shut down.
If that is the case or your business is such that you cannot shut down the systems, then you will need to use backup software that makes continuous incremental backups to allow the systems to continue to operate.
The answer to the question also answers the online versus offline backup question. Backup data that is required immediately is kept on local storage, and perhaps moved to a medium level archive after a defined time. Data that that is not needed quite so quickly can be stored on local storage, or on removable media. Tape libraries are often used for this purpose. Longer-term archives, perhaps year‑end data kept for legal reasons is stored on magnetic media in fireproof safes, or in some cases in off-site storage vaults.
To give what might seem a glib answer to the question “How often should I backup”? – as often and as completely as possible.
One final caution. Test the backups regularly. It would not be the first time that a backup set has been corrupt, or a seemingly operational backup device has written nothing to the backup media.