Discus backups are created in the TAR format, which is a standard format that can be opened, read, and manipulated by utilities on nearly any operating system. (On Windows, WinZip is one program capable of reading this format.) Discus is capable of reading TAR files that were created in the Backup Manager as well as many TAR files created by other utilities.

If your server supports the Compress::Zlib module, a compression option will be available in your Backup Manager. Compressing the backup can result in a final file size of only 10% (or less) of the original size, which can improve the time it takes to download the file from your server to your computer by ten times or more. If the Compress::Zlib module is not available on your system, compression will not be available in the Backup Manager.

When files are compressed, it is done using a format compatible with the GNU 'gzip' and 'gunzip' commands. These files can also be handled by utilities on nearly any operating system, including unix (with standard gzip and gunzip utilities) and Windows (with WinZip).

If your server does not have the Compress::Zlib module installed, the server administrator can obtain the module from CPAN and install it onto the server:

http://www.cpan.org/modules/by-module/Compress/