To sample memory dumps in a disk which can be referred from all the nodes in a cluster and to refer to it from other nodes including a cluster management node as well.

In this cluster system having a plurality of nodes 30 and 40, it is provided with the cluster management node 10 to be connected with the plurality of nodes via a network LAN 1, a shared disk 50 to be connected with the respective nodes including the cluster management node via an exclusive bus 2 and a means to store the memory dumps of the respective nodes when a fault is generated in the shared disk by being instructed by the cluster management node and to refer to the memory dumps stored in the shared disk from the respective nodes. The cluster system is further provided with optional hosts 20 connected with the network and the exclusive bus respectively and the optional hosts take charge of a part of functions of the cluster management node by being instructed by the cluster management node.