Isolating archive contents

A KDar archive stores information about its files at the end of the archive in a table of contents, or a “catalog” in dar lingo. When creating a differential backup based on an existing “reference” archive, KDar only needs to scan the reference archive's catalog to determine changes in filesystem with respect to the reference archive.

KDar can “isolate” the reference catalog into its own archive. The isolated catalog archive is almost equivalent to the reference archive, except that it contains none of the actual stored data. Since the isolated archive is much smaller than the reference archive, you can store it on your filesystem and use it for making differential backups, i.e. use the isolated archive as your reference archive.

Isolating an archive is just a matter of selecting Archive->Isolate, and providing a descriptive name. I recommend using the basename of the archive that you are isolating the catalog from, with “-cat” appended to it to indicate that this is a catalog archive.

You can open the isolated archive in KDar and display the contents. The status field will display [InRef] to indicate that the actual file data is stored in the reference archive. Currently, you have to open the appropriate reference archive in order to restore the data. A future version of KDar will handle this automatically.