As an alternative to, or in addition to VOLUME FULL THRESHOLD, consider using the MARK VOLUME FULL AT FIRST WRITE-FAILURE OPTION parameter. If the application using the storage group stores objects that have a wide variety of sizes, use this parameter so the volumes are marked full as determined by the ability of the volume to contain the object. If there is insufficient space on the volume for the object, choosing this parameter causes a volume to be marked full and an alternate volume to be chosen. For example, a request to write an object larger than 30 KB causes the demount of a volume with a full threshold of 20 KB if there is less than 30 KB free, space, in preference to a volume that contains sufficient space. If only the VOLUME FULL THRESHOLD parameter is used, the volume is not marked full; if the MARK VOLUME FULL AT FIRST WRITE-FAILURE OPTION parameter is used, the volume is marked full.

An additional side effect of not marking volumes full is the potential for additional volume mounts. A volume is selected according to its ability to contain the next object written with the intent of filling that volume. If there is a small amount of free space, the volume might be mounted to write one object. If the next object does not fit on that volume, it is demounted to mount another volume that is capable of containing the next object.