----------------------------------------------------------------- STACKER NOTE STACKER NOTE BACKING UP STACKER DRIVES (Applies to Stacker 4.0) STAC FAX 4403 (02-08-1994) ----------------------------------------------------------------- BACKGROUND You can use your favorite backup program, like Fastback, Norton Backup, or the DOS backup program to back up your Stacker drives. A Stacker drive may be backed up like any other drive. If you compressed drive C, have your backup program back up the files on Stacker drive C. COMMON QUESTIONS Which drive do I back up? Do I back up the STACVOL file? Are the backed up files compressed? How do I restore my backup made on a Stacker drive? How do I read the Stacker Toolbox Backup Status Gauge in Windows? Which drive do I back up? Back up your compressed drive(s) as you normally would. If you have left any of your drives uncompressed and have installed programs or data on them, you should back them up also. You do not need to back up the small uncompressed drives that are created when you compress your drives. In order to determine which drives are the uncompressed "host" drives, go to the DOS prompt and type: STACKER You will see a display something like this: Drive C was drive C at boot time [ D:\STACVOL.DSK = 102.3MB] Drive D was drive D at boot time In this example, the C drive is compressed and the D drive is its uncompressed physical drive. Back up the C drive and not the D drive. Do I back up the STACVOL file? Your backup software may display a large hidden file on your uncompressed drive called STACVOL.xxx. This file is the file that contains all of your compressed data. When you back up the Stacker drive, you have already backed up the contents of the STACVOL file, and you do not need to back it up again. Are the backed up files compressed? Stacker uncompresses files as they are read from the hard drive. They are then handed to the backup software in their original, uncompressed state. If the backup software uses compression, it will recompress the files before storing them to diskette or tape. This means that the files can be restored to any drive, compressed or not. How do I restore my backup? Restore your backup to any drive in the same way that you normally would. You should remember that your backed up data is uncompressed. If you restore it to a drive that does not have Stacker running, it will also be uncompressed on the target hard drive. This means that if you have had a major disk crash and are restoring your backup to that drive, you must first run the Stacker SETUP on that drive in order for the restored backup to be compressed. This may be important if the drive is not physically large enough to hold all of the backed up data. How do I read the Stacker Toolbox Backup Status Gauge? The Backup Status Gauge displays how much of your drive has not been backed up. It does this by examining the files on your drive for the archive bit. The archive bit is a DOS attribute that is "set" on each file whenever it is created or modified. Most backup programs "clear" this attribute whenever they back up a file. The backup programs can use the archive attribute to keep track of files that have changed since the last back up. In the same way, the Backup Status Gauge can report the same files by telling you what percent of your files have the archive bit set. See your DOS documentation for further information on the archive attribute. Note Not all backup methods clear the archive attribute. If you use such a method, the Backup Status Gauge will not show your disk's true status. ----------------------------------------------------------------- Copyright 1994 Stac Electronics