A method, apparatus, and computer instructions for managing frames. Frames intended for isolation are identified in which the frames include in-use frames and free frames. Reservation of free frames from the frames identified as intended for isolation is requested. Successfully reserved frames are moved to an isolation list. In-use frames are marked, and unisolated/unmarked frames are identified. Any free frames in the unisolated frames are moved to the isolation list. In-use frames in the unisolated frames are marked and reservation of the in-use frames in the unisolated frames is released.