The volume integrity check compiles a list of all frame IDs in the clip libraries on the system disk. It then queries the framestore to verify the status of each frame, and compares it to the frame ID data in the list. Each frame on the framestore has one of three statuses—used, unused or free.

UsedThe frame is used in a clip.

UnusedThe frame has been deleted in the application (though it still physically exists on the framestore until that area of the framestore is needed for another frame).

FreeThe storage associated with the frame ID is no longer available (the frame is no longer recoverable).

If the integrity check detects frames that have IDs in the library but have a status of unused on the framestore, it fixes them by changing their status to used.

Also, if the check finds any frames that are used in the framestore but are not listed in the compiled library list, it creates a clip out of them, which it places in the Lost+Found clip library. The order of these frames will be the order in which they were created.

Lastly, if the check finds frame IDs in the library list for which there are no corresponding frames on the framestore, it reports them as invalid frames in an error message displayed at the end of the check. Invalid frames occur if Stone and Wire was prevented from writing new frames to the framestore during a work session, for example, because of a system failure or power failure. By default, Stone and Wire updates itself every 300 seconds or after 2000 changes occur, whichever comes first. A change includes the creation of a new frame or any change made to an existing frame. Therefore the maximum amount of work that could be lost from this situation is 300 seconds, or 5 minutes of work.