Patent ID: 8327186

Claim:
A method for taking over ownership of an aggregate set of a primary node by a plurality of partner nodes in a cluster storage system having a shared storage, the plurality of partner nodes comprising partner node A and partner node B, the aggregate set comprising first and second aggregate sub-sets, each aggregate sub-set comprising one or more aggregates in the shared storage owned by the primary node, the method comprising: receiving, at the primary node, write requests for the aggregate set and producing write logs representing the write requests; distributing the write logs to partner nodes A and B for local storage at partner nodes A and B; determining an initiating event for takeover of ownership of the aggregate set of the primary node; retrieving and scanning an aggregate failover data structure (AFDS), the AFDS specifying, for the first aggregate sub-set of the primary node, a first-ordered partner node, comprising partner node A, assigned to take over the first aggregate sub-set upon failure of the primary node and a second-ordered partner node assigned to take over the first aggregate sub-set upon failure of the primary node and the first-ordered partner node, and specifying, for the second aggregate sub-set of the primary node, a first-ordered partner node, comprising partner node B, assigned to take over the second aggregate sub-set upon failure of the primary node and a second-ordered partner node assigned to take over the second aggregate sub-set upon failure of the primary node and the first-ordered partner node; taking over ownership of the aggregate set of the primary node by the plurality of partner nodes according to the AFDS comprising partner node A taking over ownership of the first aggregate sub-set and partner node B taking over ownership of the second aggregate sub-set; performing, at partner node A, write logs for the first aggregate sub-set; and performing, at partner node B, write logs for the second aggregate sub-set.