Backup

Many people outside the IT industry and even many fairly new to it underestimate the importance of backups – at least until such time as a disaster strikes. However, even many of those who do perform regular backups fail to recognise that the reason to backup is so that we can perform a restore.

Verify

Without the ability to restore what you have backed up you may as well not bother. What does this mean in practical terms? It means backups need to be tested to verify that what was backed up is both what you though was being backed up and that the data can be read back again. The value of periodic test restores simply cannot be overstated.

Ok, we perform regular backups and test restores, so we are confident of the value of those backups. What else needs to be considered? Location and longevity.

Location

Far too many people, even seasoned professionals, make the mistake of storing the backups near the computers that are being backed up. That’s fine if the hard drive of the computer goes bad and needs to be replaced. In that case just restore from your backup and all’s well in the world.

What happens if there is a fire or other disaster that destroys the backup along with the backed up system? If you value your data you will store it in a different location. Just how and where will depend a lot on how valuable your data is to you and the resources at your disposal. e.g. For many small businesses this consists of someone taking the backup home with them each night. For a large business it will more likely be picked up by a specialist storage company, which stores the backups in fireproof/bombproof vaults.

Longevity

How long must your data be reliably backed up? A day, a week, a decade? This will have an impact on what storage medium is appropriate. Many people these days use portable hard drives for backups, without understanding the risks. Other use CD/DVD or USB memory sticks (AKA thumbdrives). Others, mostly those with more experience and a larger budget, will use tapes.

Media Shortcomings

Hard drives are surprisingly delicate devices that can be made utterly useless by a single drop onto a hard surface. Lesser knocks or jars can make parts of the drive quite unreadable.

CD and DVD media is relatively short term at best. They become unreliable in as little as a year. Even less if exposed to UV light, such as sunlight or fluorescent lighting. If you must use them keep them stored in a cool dark place (not in the fridge).

USB drives are temperamental little beasts. Fantastic for short term storage of non-critical data but dangerous for use as backup media. They can fail catastrophically at any time, something most of us learned only too well.

Tapes, or at least proper backup tapes (not the old style cassette tapes), have only two significant potential problems. They don’t like high heat, such as being left on the back shelf of a car in summer, or very strong magnetic fields. As neither of these are serious problems for most people tapes are by far the best way to go if you have the budget.  While the tapes themselves are not overly expensive, the tape drives are anything but cheap.