Cannot delete old snapshots to free up space (Internal Server Error)

Problem

When attempting to delete snapshots, "Internal Server Error" may be displayed at the top-right corner of the ggRock Web UI.

The ggRock Log may contain the following error(s) or similar:

cannot destroy 'pool0/ggrock/images/games@2020-08-29-13-49-37': snapshot has dependent clones -- -- - - >>> pool0/ggrock/images/games-old-2020-08-29-16-11-00

Solution

In the case of this example, it is necessary to delete the empty (0 bytes) image called "games-old-2020-08-29-16-11-00" to permit deleting the snapshot in question.

Additional Information

At the time this issue was experienced, a bug in the ggRock Web UI caused the display of internal data with "-old-" in the name.