Maintaining cache coherency in the presence of a network attached memory is disclosed. A computer system includes a plurality of physical nodes. An operating system is run collectively across the plurality of physical nodes. The physical nodes are configured to communicate with a network attached memory. Based at least in part on an operation to be performed with respect to page on a first physical node included in the plurality of physical nodes, the network attached memory is configured to receive a message. The network attached memory is configured to perform an action based at least in part on the received message.