Cluster applications that process large amounts of data, such as parallel scientific or multimedia applications, are likely to cause swapping on individual cluster nodes. These applications will perform better on clusters with network swapping support. Network swapping allows any cluster node with over-committed memory to use idle memory of a remote node as its backing store and to “swap” its pages over the network. As the disparity between network speeds and disk speeds continues to grow, network swapping will be faster than traditional swapping to local disk. We present Nswap, a network swapping system for heterogeneous Linux clusters and networks of Linux machines. Nswap is implemented as a loadable kernel module for version 2.4 of the Linux kernel. It is a spaceefficient and time-efficient implementation that transparently performs network swapping. Nswap scales to larger clusters, supports migration of remotely swapped pages, and supports dynamic growing and shrinking of Nswa...