Each time a tape is mounted, Canister will create a Catalog for it. Canister Catalogs are special folders containing tiny stubs for each file on your tape, and are mounted as a read-only disk each time Canister opens.

Catalog History

As Canister creates a Catalog when mounting, and updates it after each Archive, old Catalogs are archived as well and moved into a hidden folder named LTO Tape (serial).history

Enable Finder to show hidden files to see previous generations of your Catalogs, with the Finder shortcut Shift-Command-.

Editing and removing Catalogs

To clean up the Catalog, or remove for instance test entries, you can open the original location where the stubs are saved by Alt/Option-Clicking the Catalog icon in Canister. This will open Finder in ~/Library/Application Support/Canister/Catalogs.

Retrieving files using Catalogs

Currently, it's not yet possible to use Catalogs to tell Canister which files to retrieve. This is on the roadmap, together with importing and exporting of Catalogs.