A computer-implemented method, apparatus, and computer program product are disclosed for managing direct memory access (DMA) write page faults using a pool of substitute pages. A computer system platform resolves a DMA write page fault for a page that is dedicated to an Input/Output (I/O) adapter. The I/O adapter attempts to write DMA data to the page. A determination is made that the page is unavailable for writing. The DMA data is then written to data locations in a substitute page that was selected from the pool of substitute pages. A flag is then set in a flag location for each one of the data locations. The flag locations correspond to the data locations. When a flag is set, the flag indicates that DMA write data is present in the data location that corresponds to that flag's flag location.