I created a cache using an auxiliary indexed disk cache. Calling clear() on the cache does not free disk space allocated by the disk cache. I suspect this also affects other auxiliary caches.
In fact, adding new objects to the cache using the old keys, keeps allocating more disk space.
E.g.: create cache, store a BLOB of 1 MB with key "A". 1 MB disk space is allocated for the BLOB. Now call clear() on the CacheAccess object. Store another 1 MB BLOB with key "A". Now 2 MB are allocated.
Calling AuxiliaryCache.removeAll() on the disk cache frees the disk space, though.