Abstract: A data coherence system includes a generation number written to a data track of a logical sub-system. The generation number is compared to a corresponding generation number in a processing device when it is initialized. If the two generations numbers are the same, the generation numbers are incremented and saved. If not, cache associated with the logical sub-system residing within the processing device is erased and the generation numbers are reset.

Abstract: A data coherence system includes a generation number written to a data track of a logical sub-system. The generation number is compared to a corresponding generation number in a processing device when it is initialized. If the two generations numbers are the same, the generation numbers are incremented and saved. If not, cache associated with the logical sub-system residing within the processing device is erased and the generation numbers are reset.

Abstract: A data coherence system includes a generation number written to a data track of a logical sub-system. The generation number is compared to a corresponding generation number in a processing device when it is initialized. If the two generations numbers are the same, the generation numbers are incremented and saved. If not, cache associated with the logical sub-system residing within the processing device is erased and the generation numbers are reset.

Abstract: An apparatus, system, and method are disclosed for global metadata copy repair. The apparatus includes a control module for copying global metadata from primary storage to target storage, a verification module configured to identify invalid tracks in the global metadata, a location module configured to maintain a current read address, and a read module configured to find a valid copy of the invalid tracks. The system includes a plurality of hosts, a storage controller in communication with the plurality of hosts over a network, a primary storage device, a target storage device, and the apparatus. The method includes copying global metadata from a primary storage device to a target storage device, identifying invalid tracks in the global metadata of the primary storage device, maintaining a current read address of a buffer read, and finding a valid copy of the invalid tracks.

Abstract: A data coherence system includes a generation number written to a data track of a logical sub-system. The generation number is compared to a corresponding generation number in a processing device when it is initialized. If the two generations numbers are the same, the generation numbers are incremented and saved. If not, cache associated with the logical sub-system residing within the processing device is erased and the generation numbers are reset.

Abstract: Provided are a method, system and program for updating data shared among systems. A first and second systems maintain a first and second copies, respectively, of shared data stored in a storage device. The first system obtains a first lock to the shared data, wherein the first lock applies to the first system accessing the shared data. The first system sends to the second system a first message requesting a second lock to the shared data, wherein the second lock applies to the second system accessing the shared data; The second system obtains the second lock to the shared data for the first system in response to the first message sends to the first system a second message indicating the second lock to the shared data was granted.