Abstract: A system, method, and computer program product for performing a non-disruptive service action to a storage device. A storage system with a volume receives a firmware update for storage devices supporting the volume. A controller checks whether a storage device from the volume may go offline without interrupting regular input/output with the volume. The update may proceed if the volume will not enter a failure state. The volume continues responding to input/output requests while the service action occurs. The storage device is taken offline, the update occurs, and writes to the storage device are tracked during the offline period. After the storage device is back online, any sections of the storage device that have changed due to the tracked writes are rapidly reconstructed, bringing the storage device back to an optimal state in a shorter period of time than otherwise possible, while still allowing input/output during the update process.

Abstract: Disclosed is a method of reading and writing data to and from a transactional database using a scatter-gather routine that minimizes the time in which the database is subject to a transaction lock. Data is placed in a scatter-gather list in RAM, which speeds the process of reading and writing data to the database. Further, a process is disclosed for restoring data in a transactional database that is accessed by more than one controller. An alternate controller is held in reset mode and placed offline, so that data in the transactional database cannot be changed during the restoration process. In addition, the database is placed offline and the host is notified that the database is invalid, so that the host cannot access the transactional database.

Abstract: Disclosed is a method of reading and writing data to and from a transactional database using a scatter-gather routine that minimizes the time in which the database is subject to a transaction lock. Data is placed in a scatter-gather list in RAM, which speeds the process of reading and writing data to the database. Further, a process is disclosed for restoring data in a transactional database that is accessed by more than one controller. An alternate controller is held in reset mode and placed offline, so that data in the transactional database cannot be changed during the restoration process. In addition, the database is placed offline and the host is notified that the database is invalid, so that the host cannot access the transactional database.

Abstract: Data is cached in a dual-controller storage array having a first cache controlled by a first controller, a second cache controlled by a second controller, and a shared array of persistent storage devices, such as disk drives. When one of the controllers receives a write request, it stores the data in persistent storage, stores a copy of that data in the first cache, and transmits identification data to the second controller that identifies the data written to persistent storage. Using the identification data, the second controller invalidates any data stored in the second cache that corresponds to the data that the first controller wrote to persistent storage. If a controller receives a read request, and the requested data is validly stored in its cache, the controller retrieves it from the cache; otherwise, the controller reads the requested data from persistent storage and caches a copy of the requested data.

Abstract: Data is cached in a dual-controller storage array having a first cache controlled by a first controller, a second cache controlled by a second controller, and a shared array of persistent storage devices, such as disk drives. When one of the controllers receives a write request, it stores the data in persistent storage, stores a copy of that data in the first cache, and transmits identification data to the second controller that identifies the data written to persistent storage. Using the identification data, the second controller invalidates any data stored in the second cache that corresponds to the data that the first controller wrote to persistent storage. If a controller receives a read request, and the requested data is validly stored in its cache, the controller retrieves it from the cache; otherwise, the controller reads the requested data from persistent storage and caches a copy of the requested data.

Abstract: A data storage system and a method of managing data in the storage system. A method of performing a write to a data storage system, including a first storage device and a second storage device, may include writing a first set of header information to a first storage device and a second storage device. The first set of header information includes a first sequence number and a second sequence number, in which the first set of header information includes a first sequence number incremented to indicate a change from the second sequence number. The method may also include returning status of completion of writing the second set of header information. Invalid data or an interruption may also be detected by examining the first and second sequence numbers. Data is written to the first storage device and the second storage device. Then, a second set of header information is written to a first storage device and a second storage device.

Abstract: Accordingly, the present invention is directed to a method of managing data in a storage system. A method of performing a write to data storage system, including a first storage device and a second storage device, may include writing a first set of header information to a first storage device and a second storage device. The first set of header information includes a first sequence number and a second sequence number, in which the first set of header information includes a first sequence number incremented to indicate a change from the second sequence number. Data is written to the first storage device and the second storage device. Then, a second set of header information is written to a first storage device and a second storage device. The second set of header information includes a first sequence number and a second sequence number, in which the second set of header information includes a second sequence number incremented to correspond to the first sequence number.