With apologies to Lennon and McCartney, you may have seen this parody of their song Yesterday regarding backups..

Yesterday,
All those back-ups seemed a waste of pay.
Now my source files have all gone away.
Oh I believe in yesterday.

Suddenly,
There's not half the files there used to be,
And there's a milestone hanging over me.
The system crashed so suddenly.

I pushed something wrong
What it was I could not say.
Now all my data's gone
and I long for yesterday-ay-ay-ay.

Yesterday,
The need for back-ups seemed so far away.
I knew my data was all here to stay,
Now I believe in yesterday.

Although the parody is clever, anyone who has lived through the loss of data and the enormous amount of time wasted trying to recover valuable information doesnt feel very clever after the fact. If this hasnt happened to you and you are still not performing back-ups then be warned, it is only a matter of time.

So unless you want to be singing this sad refrain you need to back up your data.

There are a number of options available for you:

A second hard disk - If you install a second drive that is the same size as your existing disk you can copy or mirror the data onto the second drive. Although the price of hard disks is falling and mirroring disks is relatively easy, having all your data on one machine leaves you vulnerable to any issues that render that computer unusable, including theft.

Recordable Media - Computers are now being shipped without floppy disk drives and even if they were still included the amount of data that is being backed up is too much for these to be of any value. The next level up from floppy disks, Zip disks, has now given way to recordable CDs (CD-Rs), and recordable DVDs (DVD-Rs). CD-Rs can hold up to 700 MB of data and DVD-Rs can hold up to 8.5 GB. Depending upon the size of the data that you want to back up these may be acceptable, however you could end up spending a lot of time burning an increasing number of disks as the size of your data increases.

Tape Back-Up data is written onto a tape. The amount of data on a tape can vary from hundreds of kilobytes to several gigabytes. Just as the amount of data can vary, so can the speed of transfer. Online back-up services allow you to upload your data over the internet to a server at a remote location. If you lose data and need to restore, you log onto the back-up service site and download your files. Because you are restoring over the Internet, backup and restoration speed can be a function of your connection speed. Of course you will need to have Internet access to restore. Some companies are still wary of having all of their business data residing on a machine that is not under their control.

Software back-up programs like the one that comes bundled with WindowsXP, or that can be purchased separately ( Norton ) are not replacements for the other methods, however, they do automate the process by sending your data to the location that you choose.

Once you have decided on you method of back-ups there are a few other items that you need to think about as well. What do you back-up? how often and where do you store the data? Who in your organization is responsible for making it happen?

It is best to have a back-up done every day of your most important files. You may even copy these more often if the amount and value of the data warrants it.

Three different back-up types that you should be familiar with are:

A Full Back-up, like the name implies, contains all the files and folders that are to be backed up. This is the most complete, and the easiest back-up to restore from due to the fact that everything you need is included (if done properly). The reason this in not usually done every time is the amount of time it takes to do. You need to be aware that if this back-up was accessed it would have all of your data on it, so it is imperative that these are handled with care. These are often stored in a secure location off site in case something happens to the building.

A Differential Back-up contains files that have changed (are different) from the time of the last full back-up.

An Incremental Back-up stores all the files that have changed since the last back-up whether that is a full, differential or incremental back-up. This back-up is completed the fastest, however restoring from a number of incremental back-ups will take longer than restoring from a full back-up.

Most companies use a combination of full, differential and incremental back-ups in an effort to balance the data security with the amount of time invested in the process. No matter which of the options you choose, it is important to know that you do not have a back-up solution until you have successfully restored your data from the back-up. I know of a person who faithfully performed back-ups every day. When the computer crashed and it was time to restore, this person was crushed to learn that the only thing that was being backed up was the icon to the program. Once again, until and unless you have successfully restored from your back-up solution, you do not have a solution.