Technically GTKtalog is not limited to scanning cd's. GTKtalog can scan cd's as well as directories on your hard drive. It scans any device that can be mounted in your filesystem with "mount /path/to/device". In the unprobable case you would not have a cd drive but only an iomega zip, you would just have to specify the mount point of your zip drive in the GTKtalog preferences.
To start scanning a cd, click on the menu entry "Catalog/Add a new cd" or on the toolbar button "Add CD"
To start scanning a directory, click on the menu entry "Catalog/Add a new directory". In the "Select disk location" window, choose the root directory of the new disk. This directory must be somewhere on your filesystem. It can belong to a local disk drive or to a remote filesystem.
The options are taken from the preferences. If you would like to override these settings only for this scan, modify the check box "Retrieve information about files" and/or the scan mode. For informations on these options, see the section called Retrieve information about files in Chapter 11 and the section called Virtual file system scan mode in Chapter 11
Type the disk label then start the scan process clicking on "OK".
During the scan process, GTKtalog runs through the cd or disk to get its file structure. The only case where GTKtalog does not reference a file is when it's MIME Type matches one of the "MIME Types to skip during a scan" TODO LINK TO THE PREFERENCE SECTION. In such a case, the scan process skips this file.
Options that modify the behaviour of a scan
Pre scan options.
Scan options.
Post scan options.
Obviously, the more numerous files are, the longer is the total scan process. You can cancel it anytime clicking on the "Abort" button of the Scanning window. The disk won't be added. The "Stop" button will add the new disk in a partially scanned state.