Abstract: Fault tolerant data storage systems and methods of operating a fault tolerant data storage system are presented. In one aspect of the invention, a fault tolerant data storage system comprises: a plurality of coupled components individually including: an interface adapted to couple with a data connection and to selectively receive a plurality of transactions from the data connection; transaction processing circuitry coupled with the interface and configured to process transactions received from the interface; and analysis circuitry configured to detect error conditions within the transactions and to prevent entry of transactions individually including an error condition into the respective component responsive to the detection.

Abstract: A controller is presented comprising one or more initiators coupled to one or more targets via a transaction bus and a corresponding number of data busses. The initiator(s) receive transaction requests from external logic, buffer the transaction and assign it a unique identifier, which is passed to an appropriate target via the transaction bus. The targets receive and queue the unique identifier until it can process the transaction, at which time it prompts the initiator to provide it the buffered transaction via a data bus dedicated to the target.

Abstract: A redundant controller data storage system having a hot insertion system and method is described. In one aspect, the method of hot inserting a controller in a redundant controller system includes configuring a first controller to include a first memory, a task processor and a system operation processor. The first memory includes a first memory image. The redundant controller system is operated via the first controller. The system operation commands are processed via the system operation processor. A second controller including a second memory, is inserted into the redundant controller system. Background tasks are processed during the processing of system operation commands via the first controller using the task processor, including copying the first memory image to the second memory.

Abstract: Fault tolerant data storage systems and methods of operating a fault tolerant data storage system are presented. In one aspect of the invention, a fault tolerant data storage system comprises: a plurality of coupled components individually including: an interface adapted to couple with a data connection and to selectively receive a plurality of transactions from the data connection; transaction processing circuitry coupled with the interface and configured to process transactions received from the interface; and analysis circuitry configured to detect error conditions within the transactions and to prevent entry of transactions individually including an error condition into the respective component responsive to the detection.

Abstract: A redundant controller data storage system having an on-line controller removal system and method is described. In one aspect, the method of on-line removal of a controller from a redundant controller system according to the present invention includes the redundant controller system having a first controller and a second controller. Partial removal of the first controller from the redundant controller system is detected. A shut-down sequence is performed on the first controller and the second controller, including completing outstanding memory accesses. The first controller is defined to have a first memory, and the first memory is placed into a self-refresh mode. Removal of the first controller from the redundant controller system is finished.

Abstract: A redundant controller data storage system having a system and method for handling controller resets is described. In one aspect, the method of handling a controller reset in a redundant controller system according to the present invention includes the redundant controller system having a first controller and a second controller. A controller reset is detected on the second controller. The first controller is notified of the controller reset via a communication link between the first controller and the second controller. A shutdown process on the first controller and the second controller is performed. The communication link between the first controller and the second controller is disabled, wherein detection of a subsequent controller reset via the second controller cannot be communicated to the first controller via the communication link.

Abstract: Fault tolerant data storage systems and methods of operating a fault tolerant data storage system are presented. In one aspect of the invention, a fault tolerant data storage system comprises: a plurality of coupled components individually including: an interface adapted to couple with a data connection and to selectively receive a plurality of transactions from the data connection; transaction processing circuitry coupled with the interface and configured to process transactions received from the interface; and analysis circuitry configured to detect error conditions within the transactions and to prevent entry of transactions individually including an error condition into the respective component responsive to the detection.

Abstract: Redundant data storage systems and methods of operating a redundant data storage system are presented. In one aspect of the invention, a redundant data storage system includes: a plurality of storage devices configured to redundantly store digital data; a plurality of transaction originating devices configured to originate a plurality of transactions to control operations of the storage devices; a plurality of parallel data buses configured to communicate data relative to the respective transaction originating devices; and a plurality of transaction processing devices coupled with the parallel data buses and configured to process the transactions in an order according to a transaction ordering protocol common to at least some of the transaction processing devices.

Abstract: A redundant controller data storage system having a hot insertion system and method is described. In one aspect, the method of hot inserting a controller in a redundant controller system includes configuring a first controller to include a first memory, a task processor and a system operation processor. The first memory includes a first memory image. The redundant controller system is operated via the first controller. The system operation commands are processed via the system operation processor. A second controller including a second memory, is inserted into the redundant controller system. Background tasks are processed during the processing of system operation commands via the first controller using the task processor, including copying the first memory image to the second memory.

Abstract: A redundant controller data storage system having a system and method for handling controller resets is described. In one aspect, the method of handling a controller reset in a redundant controller system according to the present invention includes the redundant controller system having a first controller and a second controller. A controller reset is detected on the second controller. The first controller is notified of the controller reset via a communication link between the first controller and the second controller. A shutdown process on the first controller and the second controller is performed. The communication link between the first controller and the second controller is disabled, wherein detection of a subsequent controller reset via the second controller cannot be communicated to the first controller via the communication link.

Abstract: Redundant data storage systems and methods of operating a redundant data storage system are presented. In one aspect of the invention, a redundant data storage system includes: a plurality of storage devices configured to redundantly store digital data; a plurality of transaction originating devices configured to originate a plurality of transactions to control operations of the storage devices; a plurality of parallel data buses configured to communicate data relative to the respective transaction originating devices; and a plurality of transaction processing devices coupled with the parallel data buses and configured to process the transactions in an order according to a transaction ordering protocol common to at least some of the transaction processing devices.

Abstract: A redundant controller data storage system having an on-line controller removal system and method is described. In one aspect, the method of on-line removal of a controller from a redundant controller system according to the present invention includes the redundant controller system having a first controller and a second controller. Partial removal of the first controller from the redundant controller system is detected. A shut-down sequence is performed on the first controller and the second controller, including completing outstanding memory accesses. The first controller is defined to have a first memory, and the first memory is placed into a self-refresh mode. Removal of the first controller from the redundant controller system is finished.

Abstract: Individual devices of a redundant array of independent devices (RAID) are coupled to an electrical power supply. For devices having widely varying load impedances, such as disks, incident with the coupling of electrical power thereto, the replacement or addition of a device in the system, while the system is in operation, causes unacceptable power transients in the power supply. To minimize such power transients, a transient suppression circuit is employed to isolate the load impedance of the device from the power supply. Isolation is achieved in the transient suppression circuit by employing an active circuit element, such as a MOSFET power transistor, as the power coupler. A capacitor controlled voltage divider circuit, incident with the coupling of electrical power thereto, couples a time varying gate voltage, which changes as a function of the rate of charge of the capacitor, to the MOSFET power transistor.