1. A cluster storage system comprising: a shared storage comprising a plurality of storage devices; a plurality of nodes connected with the shared storage for providing data-access service to the shared storage, the plurality of nodes comprising a primary node and at least one partner node configured for resuming data-access services of the primary node upon failure of the primary node, each node configured for: producing write logs for received write requests; communicating the write logs to a global write-log device at predetermined time intervals; and the global write-log device connected with the plurality of nodes, the global write-log device configured for: receiving and storing write logs from each node; detecting a failure of a node by monitoring time intervals of receiving write logs from a node; and upon detection of failure of the primary node, providing the write logs of the primary node to the at least one partner node, each node communicating write logs only to the global write-log device, wherein write logs are not communicated between nodes in the cluster storage system and each node does not store write logs of another node in the cluster storage system.