APPARATUS AND METHOD FOR REBUILDING A LOGICAL DEVICE IN A CLUSTER COMPUTER SYSTEM

Apparatus and methods for rebuilding logical I/O devices in a cluster computer system. The apparatus include controllers programmed to cooperate towards this end. The apparatus has first and second nodes with respective bus controllers communicatively coupled to each other and to the logical I/O device by means of a bus. The first controller receives a request to rebuild the logical I/O device and, in response, conditionally communicates a rebuild request for the logical I/O device over the bus to the second controller. (The logical I/O device can be a logical device depending from a multi-logical-device, third controller.) Before conditionally communicating, the apparatus determines whether a rebuild of a logical I/O device is already in progress and, when a rebuild is already in progress, aborts the new request to rebuild. When an rebuild is not already in progress, the apparatus then sets a state variable to indicate that a rebuild is now in progress. The apparatus determines whether the first controller receiving the rebuild request is a master controller, and when it is not, communicates from the first, receiving controller to the master controller a rebuild request for the logical I/O device. The master controller directs the rebuilding of the logical I/O device, including determining within which controller the logical I/O device is reserved, and when the reserving controller is not the master controller, communicating from the master controller to the reserving controller a rebuild request for the logical I/O device. The reserving controller rebuilds the logical I/O device.