Backup and Recovery

Considering the importance of backups for small to medium businesses in Hampshire;

...Imagine that you own an incredibly successful business, you are swamped with orders everyday and you receive many testimonials a week which are immediately placed onto your website.

You don't need to advertise because most of your customers are sold on the praise they hear regarding your product and services from other ecstatically happy customers. When you do advertise it doubles your client base and also your annual profit. All of your customers' details and invoices are stored on your computer systems.

One day, there is a huge electrical storm. Luckily you miss it because you are on holiday, but on your return you discover that all of the data stored on your computer system has been wiped. This could potentially be the downfall of the business that you worked so hard to develop.

Hopefully everyone reading this will be chorusing "but what about the backups?" If so then this article will read as a lesson in common sense. It will be of more benefit to those out there who think that backing up their data and system state is too time-consuming, too expensive or simply not applicable to their circumstances. Sure, they could argue that the chance of a severe enough storm near their premises to corrupt the computer's storage device is unlikely, but there are other events that could jeopardise the future of a business by eradicating data;

• Fire
• Water damage
• Malicious damage
• Accidental deletion of data
• Computer viruses
• Corruption of files due to age of hardware
• Power surges

I'm sure that you can name more. Having a disaster recovery program in place should be on the essentials list for any company that uses computers. If a computer network is central to the everyday running of your business then you must ensure that you backup your data in such a way that your business could recover from a disaster such as those mentioned above.

But backing up data is not only important in minimising the effects of a disaster on your company's valuable database; it also makes routine network administration less stressful by creating a safety net. Suppose registry entries were incorrectly changed, or an important file or piece of software was accidentally deleted, if regular backups were scheduled these errors could be easily fixed. So how do you backup your system, and how often should you do so? Well, there are three main forms of backup, each with their advantages and disadvantages;

• Full Backup - As you can probably guess, this involves backing up all of your data. This method is the most time-consuming, but provides the easiest method of disaster recovery. If you don't have the time to perform full backups three times a week, there are some alternatives which will help reduce the number of full backups you need to do to ensure that your data is safe.

• Incremental Backup - This is the fastest form of backing up data. It backs up only the changes made since the last incremental or full backup. The downside is that to restore your data you will need the last full backup along with all of the subsequent incremental backups that have been done. This makes the incremental method the longest method to restore, although hopefully you will be backing up more that restoring.

• Differential Backup - These are similar to incremental backups in that you will need to perform full backups. Each differential backup stores the changes made since the last full backup, so to restore the data you need only have the last full backup and the most recent differential backup. With this you get the best of both worlds, while not as easy a disaster recovery method as explicitly using full backups, it is far less time consuming than using full backups and requires less to recover than incremental backups.

How often you backup is important. It is recommended that backups be made for every four to ten hours of data entry. For some businesses this could be everyday. An IT company that provides a backup service would be able to give you some idea of the schedule that best suits your business.

An IT company should also give you advice about where to keep your backups. It is possible for example to back your system data onto another partition of the drive it is usually stored, but for disaster recovery purposes this is not very sensible because should anything corrupt or damage that hard drive then you would lose your backups along with your data. The next step up would be to backup to a separate drive within the same server using mirroring. The data on the original drive would be safely stored on a different drive, but what about that burst water pipe or fire? This is still not an ideal disaster recovery plan.

Tape drives and other mass storage devices (such as external hard drives) are perfect because they can be removed from the original location of the data. It is wise to store your backed up data in a separate room or preferably building as the same fire, flood, theft etc that is destroying your server could also permanently damage your backups.

So, now that you know why you should develop a disaster recovery plan, how different methods of backing up data can reduce the time it takes to successfully do so and where you should be storing your backed up data, you should be in a position to relax. As long as your data is backed up (and in some regards your business too) you can know that should an unexpected disaster occur, your customers will be none the wiser, and your business will remain undamaged.