With Backup, you can back up files from a local or network hard drive to a removable disk, a network drive, or a tape drive that is attached to your computer. Before you back up files, it is a good idea to develop a backup strategy. A backup strategy is a method for regularly backing up your work that balances tradeoffs between safety, time, and media space. For example, if safety were your only concern, you could back up your entire hard drive every hour . But you would not have any time to work, and you would spend a fortune on backup tapes. If spending minimal time and money on backups were your only concern, you might back up only a few crucial files once a month. The best choice is a balance between the two extremes. The backup medium that you use to store backed up files from a hard drive is usually a set of removable disks or a tape cartridge designed to store computer data. Removable disks and tape cartridges are large capacity backup media that require special hardware on your computer, such as a zip or tape drive. This extra expense may be worthwhile if you depend on your computer for business.
Because backups take time each time you perform them, you should back up only the files that change on a regular basis; back up all of the files on your computer at less frequent intervals. For example, because software program files don't change, you can easily reinstall them from their original program CDs or disks, so you do not need to back them up as often as your personal document files, which might change on a daily or weekly basis. Ask yourself how much work you can afford to lose. If you cannot afford to lose the work accomplished in one day, then you should back up once a day. If your work does not change much during the week, back up once a week.
Depending on the number and size of your files and the backup device you are using, the backup can take a few minutes to a few hours to complete. If you are planning to back up large amounts of information, such as your entire hard drive, it is best to start the backup at the end of the day and use a large capacity tape or removable disk, if possible, so you do not have to swap multiple disks. When a file does not fit on a tape or disk, Backup splits the file, fitting what it can on the current disk and then prompting you to insert the next tape or disk. When you perform a backup, Backup creates a backup set , also known as a backup job , which contains the compressed copies of the files you backed up. The backup job is stored in the backup file with the .bkf extension. You can store more than one backup job in a specified backup file. There are several different methods for backing up files with Backup:
A normal backup copies all selected files to the backup medium, regardless of when the files were last changed and clears the archive attribute for each file in order to mark the file as backed up. An archive attribute is an internal Windows file marker indicating whether a file needs to be backed up.
An incremental backup copies only the files that have changed since your most recent normal or incremental backup. It also clears the archive attribute for each file that is backed up. Therefore, the first incremental backup after a normal backup copies all files that have changed since the normal backup, and the second incremental backup copies only those files that have changed since the first incremental backup, and so on.
A differential backup copies only the selected files that have changed since your most recent normal or incremental backup. Unlike incremental backups, however, the archive attribute is not cleared during a differential backup. Therefore, successive differential backups copy all the files that have changed since the last normal or incremental backup, not just the ones that have changed since the last differential backup. The first differential backup after a normal backup copies all files that have changed since the normal backup, and the second differential backup copies all the files that have changed since the normal backup, including all files that changed from both differential backups. Since differential backups copy more changed files, they take longer than incremental backups and require more disk or tape space.
A copy backup copies all selected files, like a normal backup, but it does not clear the archive attribute. Therefore, you can use it to perform a special backup without affecting your normal backup routine.
A daily backup copies all selected files that were changed on the day the backup is done. It does not clear the archive attribute. You can use daily backups to save your day's work without affecting your normal backup routine.