Methods and apparatus, including computer program products, for redundant data forwarding. A method includes, in two or more networks of interconnected computer system nodes, receiving a request from a source system in a first network to store data, directing the data to a first computer memory in a first network, directing a first copy of the data to a second computer memory in a second network, continuously forwarding the data from the first computer memory to other computer memories in the first network without storing on any physical storage device in the first network, and continuously forwarding the first copy of the data from the second computer memory to other computer memories in the second network without storing on any physical storage device in the second network.