Liveness determination in a multinode data processing system is enhanced through the use of a shared nonvolatile memory, typically a disk, which is utilized in conjunction with defined transmission protocols to provide an independent communication path usable for both the transmission of node liveness information and for other, more general, data transfer purposes. This path is considered as having the same degree of importance as other network paths and liveness indications from the shared memory path are likewise considered at the same time as liveness indications from another path or paths.