Backup Methods

Depending on the backup device, you may be able to "copy" files from the computer to the device or, you may make a "backup":

Backing-up is different than copying. When you do a "backup", the software creates one large, compressed file (containing all backed-up files). If you were to view the backup device's contents you would likely see only one or two individual files and certainly nothing you would recognize. You cannot directly view or open any individual file that was backed-up.

While backing-up makes viewing the backed-up files difficult, it can save a great deal of time and storage space. Additionally, restoring is very simple as long as your restore options are set correctly. Because the backup software kept track of what was backed-up and from where, it knows where those files need to be restored to, i.e., you do not need to be familiar with the computer's disk structure and folders.

Copying is just as it sounds, you have a like-for-like copy on the computer and backup device. This method is more applicable to "dragging and dropping" to CDs and removable drives, i.e. If you were to view the backup device's contents, you would see an exact duplicate of your hard drive (or at least those files you selected to backup). You may even be able to open a backed-up file directly from the backup device.

While copying makes backing up and viewing the backup device's contents easy, restoring is a more of a challenge. To restore you must know exactly where the files need to be restored from and more importantly, where they need to be restored to, i.e. you must be familiar with the computer's disk structure and folders.

There are two important terms used during the backup and restore operations, they are "Source" and "Target" (sometimes referred to as the "Destination".) These refer to your hard drive and backup device. When backing up, the source is the computer's hard drive and the target is the backup device (CD, tape drive or whatever.) When restoring these two terms are inverted so the backup device is now the source!

Backup Options

Under a true backup system such as a tape unit, there are different options but first a little needed information...

Every file has certain properties such as a date created, date modified, size and so on but of relevance here, all files have an archive-bit property. The archive-bit is a true/false setting of the file. When this setting is true, it means the files needs to be backed-up, i.e., the file has changed since the last backup.

This archive-bit allows backup applications to skip files that have not changed but there's a potential problem relying on the archive-bit. More on that problem shortly but first; here are the different backup options available with tape or similar devices and how the archive-bit plays a role:

Copy: backs-up all selected files (regardless of the current bit setting) but does not clear the archive-bit.
Even after a backup, the file will appear (to the backup software) as if it was not backed-up.
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Normal (or Full): backs-up all selected files (regardless of the current bit setting) and clears the archive-bit.
The file will appear to the software as being recently backed-up.
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Differential: backs-up all files that have their archive-bit set but does not clear the archive-bit.
The file will appear to the software as if it was not backed-up.
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Incremental which backs-up all files that do not have their archive-bit set, then clears the archive-bit.
The file will appear to the software as being recently backed-up.
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Daily which backs-up only files that change that day then then clears the archive-bit.
The file will appear to the software as being recently backed-up.
Warning: This option may skip files during the backup process if you skip a day in the tape rotation.

The above options are all based on a beginning normal backup.

Media rotation

It's very important to get some sort of media rotation going to include an off-site copy.

One method is to do a Normal/Full backup on Monday then on that same media, do a differential/incremental backup-up the rest of the week. The media should then have five individual backup sets. The problem with this method is; if the building burns down on Thursday, your most recent available backup is the prior week-ending.

Another method similar to above: Change medias and do a normal/full backup on Monday and Wednesday and differential/incremental backups the other days. Some schemes even say to change medias Monthly (but that's way too long for our comfort).

Whenever the media is switched; take the recently recorded media off premises.

Notes for above methods (dependant on the software and options):

Some schemes recommend labeling the media as the date the media was initially put in service, other recommend Monday, Tuesday, Wednesday, etc.

By "labeling", we are not referring to the hand written label but rather the name of the media as imprinted on the media during the initiation/format. Discussed more under the Process.
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Differential and Incremental backups may rely heavily on this media label!  So if you initially prepare a media labeling it "Monday" and use it for a normal/full backup. The Differential/ Incremental backup done the rest of the week may fail if the "Monday" media is not in the device.

Keep your rotations in order and externally labeled exactly the same as the imprinted label.
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Note: If you loose track of which is which, most backup software offers a "media view" option that will show you the label and other information.

The best method in our opinion:

Get a backup device with plenty of capacity and do a normal/full backup each and every day whereas you have at least six medias available. To start the rotation create a pile of medias with the plan of the oldest backup on the top of the pile.

The first night a full backup will be done. Then the following morning take the media out of the device and immediately put it in your car, (replacing it with the media on top of the pile.)

The third morning (and then on) bring the media in from you car, place it at the bottom of the pile, put the media at the top of the pile in the device and again, the one that came out... to your car.

This is simple, straight-forward and there is no need to label anything (as long as the pile stays straight.)

Continue to The Process