Backup

An ounce of prevention is better than a pound of cure. It's highly recommended that you make backup copies of your RDB and associated management blocks. A backup copy is always preferable to any attempt to recover the data after a disaster. It's imperative that the backup copy is not saved on the hard disk but on one or more floppies, as it doesn't help much to have a backup RDB on a hard disk struck by disaster.

The backup copy is written as a single file. This usually fits comfortably onto a single floppy disk.

Although RDB-Salv's section Salvage function does not support all file system types, the backup function is able to backup relevant information for all file system types, including NetBSD, Mac, AFS.

To create a backup copy:

1. Format an empty floppy disk. Refer to your system manual for an exact description of how to go about this if you are unsure.
2. Label the floppy disk and insert it in a drive.
3. Click on Backup. Provide the correct information in the three text gadgets:

   Device

   Device must contain the name of the device driver of the device for which you wish to create the backup. e.g. `scsi.device'. Consult your hard disk controller or host adapter manual for the name of the device driver noting that its specification is case sensitive. Click on Choose... to see all possible device drivers. Double-click on the correct name to accept it.

   Unit

   This number corresponds to the Unit number of the device. SCSI Unit numbers usually range from 0 to 6. If you don't know the number off-hand, then start up the corresponding prep program (e.g. HDToolBox) which will give you an idea of all unit numbers. Alternatively, check your hard disk manual.

   Backup-File

   Backup-File specifies the name of the file to which the backup of the RDB and associated management blocks is to be written. If you click on Choose..., a filename browser will appear so that you can choose a directory and enter a filename which should be on the formatted floppy. The backup copy should never be stored on the hard disk from which the RDB originates.

4. Set the check-mark Optimize appropriately. When selected, the backup will contain (just about) only those block which contain directly relevant data. This can significantly reduce the size of the backup copy. However, it won't backup those lost blocks which you may be able to find using the section Read page. Laymen are advised against selecting this option.
5. Click on the Start gadget to start the backup. A requester will appear when the backup has been completed successfully.
6. Just to make sure, make a copy of the floppy. Floppy disks are much less reliable than hard disks and it would be extremely annoying to discover that your backup is unusable. If need be, refer to your system manual to find out how make a copy of a floppy disk.