A method, apparatus, and program product access memory resources of a computer using a group of direct access memory (DMA) devices. A first DMA device is designated a primary device after association with an active translation table (ATT), while a second DMA device is designated a backup device after association with an inactive translation table (ITT). A translation is entered into the ATT for the first DMA device to permit it to perform a DMA operation, while a translation is inhibited from being entered into the ITT for a second DMA device to prevent it from performing a DMA operation. Thereafter, the roles of the first and second DMA devices may be swapped by associating the first DMA device with the ITT and associating the second DMA device with the ATT. The computer may be a logically partitioned computer of the type that includes a plurality of logical partitions.