Patent ID: 7650412
Filing Date: 2010-01-19
Classification: G06F,H04L

Abstract:
1. A method of claiming ownership of a plurality of disks by a network device of a plurality of network devices in a network storage system, comprising: writing ownership information to a predetermined area of each disk, wherein the predetermined area of the disk is sector setting a small computer system interface (SCSI) reservation tag for each disk to a state of network device ownership to provide a two part indicia of ownership for each disk, where the two part indicia of ownership are both written to each disk; creating a table on each network device in the network storage system; identifying all disks owned by each network device using ownership information written to the predetermined area of each disk of the plurality disks and, for each identified disk, if a mismatch occurs between the ownership information on the predetermined area of the disk and the ownership defined by the SCSI reservation tag, then using the ownership information written to the predetermined area of the disk as definite ownership data without requiring the owned network device to send a second SCSI reservation tag; in response to identifying, storing entries in the table, wherein each entry identifies an owned disk of the network device storing the table; identifying, by a second network device, all disks owned by a first network device in response to a failure of the first network device, wherein each network device can read ownership information of each disk; setting a SCSI release tag for each disk owned by the first network device, in response to the failure of the first network device, to transfer the disk to an unowned state; and removing ownership information stored in the predetermined area of each disk owned by the first network device to complete transferring each disk into the unowned state.