Continuous data protection

You never know when your computer will crash or your hard drive fail. So every computer user should have up to date backups of the files and documents on their computer. However, not many do, with the result that we sell a lot of data recovery software.

If you would prefer not to experience the shock and horror when you realize that all your work is lost, you should back up your files regularly. However, conventional backup programs are not always the best solution for home or small office computer users. This is because:

• You have to remember to run the backup, every day, and you often don't.
• Backups take time to complete, usually at a time when you want to switch the computer off or go home.
• The restore process can be cumbersome.
• Conventional backups won't let you recover work done since the last backup, which might have been last night.
• You may not keep backup archives going back a long time, so they offer no protection for files that were deleted or changed some time ago.

Continuous backup

Conventional or image backups are best for restoring an entire system without having to reinstall the operating system and software. But for day to day backup of your files, a continuous backup solution is better.

Continuous backup means that files are backed up automatically, whenever they change. Another term for this is continuous data protection. A program runs in the background, watching for changes to files. Whenever a file changes, a new backup is made, but the old copy is not deleted. This creates a version history of each file, so you can restore not just the last version, but any previous version.

With continuous backup you need never lose a file, even if you delete it by accident soon after saving it. If you make changes to a file and save them, then realize that you made a mistake, continuous backup lets you recover an earlier version, so you don't have to undo the changes manually. It's a huge time saver.

Because backing up files whenever they change could take up a lot of space, continuous backup is often only used to protect specific file types or folders, typically the files you work on every day. Clever software can also help to save space by storing only the changes made since the last backup of the file, and by using data compression. This is transparent to you, the user. If you need to restore a file you will simply see a list of copies of the file with the dates they were created.

If the hard drive fails and you only have a conventional backup, you lose everything since the last backup was taken. It is common practice to keep only a couple of generations of backups, or even overwrite the last backup with the new one, so when a file is deleted, the backup copy of it is lost soon afterwards.

With continuous backup, if you delete a file, the backup copy normally remains in the archive until you specifically remove it. This makes continuous data protection a far better solution than the Windows Recycle Bin for protecting files from being accidentally deleted.

The ability of continuous backup to provide a version history is one of its most valuable, yet least appreciated features. If you work for a long time on a file, whether it is a program source file, a web page or a report or spreadsheet, you may sometimes wish you could roll back to a previous state, or at least look at an older version. With continuous backup this is easy. Programmers use tools called version control systems (VCS) to achieve this. Continuous backup provides this capability for any type of data.

Continuous data protection for Windows

If you are using a Windows PC then you can get continuous data protection easily and inexpensively by installing continuous backup software. Once the software is installed and set up you can simply forget about it - until you find you have lost or overwritten a file that you really want, when you will be able to restore it with ease.