Patent ID: 10802933

Abstract:
Implementations are provided herein for using a Node State Block (“NSB”) to track the validity of various copies of the journal. The NSB can contain states local to the node and be implemented independent of the cluster state, and be readable at node boot time. The NSB can be mirrored to every storage drive within the node. The NSB can contain a generation number and a validity bit. Every time the NSB is updated, the generation number can be incremented. An update must be written to a quorum of drives to be considered committed. At mount time, the NSB is read from all the drives, and the copy with the highest generation number is used. If a quorum of drives cannot be read, the mount fails. Read quorum, or the quorum required at mount when reading the NSB across the set of storage drives requires a strict majority of the storage drives to have valid copies of the NSB. Write quorum, or the quorum required to update the NSB across all storage drives, requires a simple majority of drives.