窶｢Use the Topics menu in this program to view other topics of interest.
窶｢ To produce a printed copy of this guide, copy the contents to a text editing program such as SimpleText. Use the Print command of the text editing program.
窶｢ If all you need is simple backups, skip the rest of this topic. Read the Quick Start topic.
窶｢How does Drag'nBack work?
Drag'nBack is a backup program. Drag'nBack is easy to work with. Drag'nBack empowers you to devise a backup strategy that suits your particular needs. You can have fun doing backup with Drag'nBack.
When you drag icons on the desktop and drop them over Drag'nBack窶冱 icon, Drag'nBack will quickly back up the files in them. You can drag files, folders, disks, or any combination of these. You only need to tell Drag'nBack which backup disk to use. You can easily arrange backup tasks into a single grouped function on the fly, and even configure these groups into sets which can be quickly updated later.
You can think of Drag'nBack as a container窶 it remembers files that are dropped over it. It remembers the backup disks it used. If you have new files or folders to back up, drag and drop them over Drag'nBack. If you double-click on Drag'nBack窶冱 icon to open it, Drag'nBack will back up the files it remembers. Drag'nBack only backs up files that have changed since the last backup. It will prompt you for the backup disks that are needed.
A backup disk can be any Finder-mountable storage device. Drag'nBack backs up files by making a mirror image copy of the original files. A file and the hierarchical folders it is in are all duplicated in the backup disk. The location and label of the file are preserved. Thus the backup file is ready to use with most application programs.
If you think you can do a backup with the Finder邃｢, think again. The Finder's file copy is really just that. Drag'nBack, on the other hand, is a genuine backup utility. Drag'nBack updates a backup file only when the source file has changed.
Drag'nBack can also compress the backup files.
In addition to backup, you can use Drag'nBack to find files, open a document or application, delete unwanted older files, defragment a disk, synchronize files, open a folder window on the desktop, get Finder Info, make an alias file, etc.
窶｢What is a Macintosh file?
In computers all information is digitized. The basic unit of information that a computer processes is called a byte. A byte can represent one out of 256 possible kinds of information. A file is a group of related bytes. A Macintosh file consists of two groups of bytes. They are called the resource fork and data fork. A Macintosh file also contains additional information which is stored on a disk separate from the file itself. This information specifies the kind of file, the program that created it, the creation date and the last modification date, etc. Finally, the Finder allows you to type a comment about each file in the Get Info window. The comment is stored in a separate file and is used by the Finder.
窶｢Why do you need to back up files?
Philosophically, nothing is imperishable, even atoms. Your valuable files on disk are no exception. When a file has been lost, your only option is to spend hours recreating it. On the other hand, if you have made a copy of the file, you can restore it in seconds. Backing up usually involves making a copy of a file, usually to a different media. Backing up does not guarantee the eternity of your files. However, it provides a very reliable insurance against the disaster of losing files.
窶｢What can happen to files on a disk?
First of all, a disk file can be inadvertently deleted. Therefore, a lot of users feel some uneasiness when they drag files to the trash can. On the other hand, if you have backed up files, you will have peace of mind when deleting them. Even if you窶况e made a mistake, you can quickly restore deleted files from the backups.
Second, a file on disk can become corrupted. This can happen as it窶冱 being saved or after it窶冱 saved. A program can save information in memory to disk without knowing the memory is corrupted. Most of the time, a program can not open a file after it has been corrupted.
Third, the hard disk may crash either physically or by a virus, rendering total loss of files on the hard disk.
Fourth, a fire or theft may result in the loss of all your computer equipment, including the backup media.
Finally, a file changes every time you work on it and save it. Almost all applications save a file by replacing the older version on disk. Thus, you can not "undo" the changes after you quit the application. However, a backup makes undo possible on this level.
窶｢Why do you need the Drag'nBack program?
Theoretically, file copying can be done with the Finder. Some pundits have even written articles teaching you how to do it. If you work with a single file this solution may be suitable for you. However, we all know Macintosh owners use more applications than their PC counterparts in the old days. If more than one file needs backup, the copying job will quickly become tedious and time consuming.
Sure, you can drag the internal hard disk icon to the external hard disk and let the Finder back up the internal hard disk. The Finder will copy all files whether or not the files are already on the external hard disk. This practice is not only time consuming but can be risky. Drag'nBack backs up only files that have changed.
Suppose some files on the source disk become corrupted after the first backup because of hard disk error. If you use the Finder to back up a second time, your backup volume will be replaced with these corrupted files also. Drag'nBack, on the other hand, will not back up files unless they have been used and modified. If they have been used, you know they are not corrupted.
Still when a program saves a document it may inadvertently save it on a bad sector of the disk. Or a bug in the program may render the saved document unreadable the next time you tried to open it. When you back up this corrupted document the backup file becomes corrupted also. Drag'nBack provides a solution to this scenario. It is called Safer Mirror Image. You can read it in the Preferences topic.
Drag'nBack automates the copying process. It creates a template to record what files are backed up and where the backups are stored. Therefore, you need not bother about these things after the template is created. Besides other things, you use a computer to 'automate' work, to finish work faster, don't you?
A backup program is the most important of all utilities. If you have backed up all files and are struck by a computer virus, you can still recover all damaged files from the backups. On the other hand, a virus protection program will not help you with a crashed hard disk.
When your hard disk becomes crowded, a disk compression program may let you double the hard disk capacity. For practical reasons, this is not really possible because many files, such as the System file, should not be compressed. On the other hand, a backup program allows you to remove or archive unwanted files from the hard disk, thus effectively increasing your hard disk's capacity. And this is done in a very safe and convenient way. Your original files are not disturbed. If after removing files you still need more disk space, then you definitely need a bigger hard disk.
The program you can do without is a file undelete utility. If you find you have accidentally deleted a file, what do you do? Simple窶破ust restore a copy from your backup.
Drag'nBack also lets you optimize a hard disk. You can use it in place of a separate disk optimizing program. Drag'nBack also lets you synchronize files between two disks.
