Normally, you will want to leave compression on. The only time you should turn it off is if you plan to use the tape in another comparable drive that doesn't support compression. The drive that doesn't support compression will not be able to read the compressed data on the tape.

You can only change compression when a blank tape is in the drive. This prevents the ``mixing'' of uncompressed and compressed data between sessions on a tape.

To turn compression on or off:

1. Select the tape drive that you want to set.

   Refer to ``Selecting a tape drive'' for information about selecting a tape drive.

   If the tape drive supports compression, you will see either ON or OFF in the Device Information area of the Device Management window:

   

2. Click the Change Compression Mode button.

   The following dialog box appears:

   

3. Click OK to set the Compression Mode to OFF (if it is On) or On (if compression is Off).