Patent ID: 7788361
Filing Date: 2010-08-31
Classification: G06F

Abstract:
1. A method for operating a data storage system, comprising: indicating by a first indicia of ownership and by a second indicia of ownership that a selected storage system of a plurality of storage systems has ownership of a logical arrangement of storage space, and the two indicia of ownership are required to agree for the selected storage system to have ownership of the logical arrangement of storage space; issuing a request that ownership of the logical arrangement of storage space owned by a first storage system of the plurality of storage systems be transferred to a second storage system of the plurality of storage systems; changing, in response to the request, a first ownership attribute to a state of unowned; changing, in response to the request, a second ownership attribute to a state of unowned; changing, in response to the first ownership attribute and the second ownership attribute both being in the state of unowned, the first ownership attribute and the second ownership attribute to indicate that the second storage system is the owner of the logical arrangement of storage space; and maintaining a log of changes of the first ownership attribute and the second ownership attribute, the log written into persistent storage, the log permitting the request for ownership to continue in the event that either the first storage system or the second storage system becomes inoperative before the change in ownership is completed.