Abstract: The present invention is directed to an apparatus capable of dual porting a serial advanced technology attachment (SATA) disk drive in a fault tolerant communication system, such as fibre channel. The dual porting apparatus includes two idle regenerators coupled to two serial master devices, a synchronization logic capable of synchronizing the communications between one of the idle regenerators and a third idle regenerator coupled to the SATA disk drive. Furthermore the dual porting apparatus may include an auto detector capable of enabling either of the first two idle regenerators, thus effectively switching between the two.

Abstract: The present invention is directed to an architecture for transparent mirroring. A method of providing data redundancy in a data storage system may include receiving a request by a first data storage device controller for data access operation. Data is written to a local storage device and a data access operation performed by a second data storage device controller communicatively coupled to the first data storage device controller over an interconnect fabric simultaneously. The second data storage device controller communicatively coupled to a second data storage device.

Abstract: A system and method for monitoring and managing devices on a network. The system and method preferably comprises a proxy server connected to the network and a managed device connected to the proxy server. The system further comprises storage means for storing a device management application program associated with the managed device, and a management station in communication with the managed device via the proxy server and in communication with the storage means. The management station preferably is configured to retrieve the device management application program from the storage means and process the device management application program. As the management station processes the device management application program, the management station is able to monitor and manage the managed device.

Abstract: A system and method for monitoring and managing devices on a network. The system and method preferably comprises a proxy server connected to the network and a managed device connected to the proxy server. The system further comprises storage means for storing a device management application program associated with the managed device, and a management station in communication with the managed device via the proxy server and in communication with the storage means. The management station preferably is configured to retrieve the device management application program from the storage means and process the device management application program. As the management station processes the device management application program, the management station is able to monitor and manage the managed device.

Abstract: Apparatus and methods which allow multiple storage controllers sharing access to common data storage devices in a data storage subsystem to access a centralized intelligent cache. The intelligent central cache provides substantial processing for storage management functions. In particular, the central cache of the present invention performs RAID management functions on behalf of the plurality of storage controllers including, for example, redundancy information (parity) generation and checking as well as RAID geometry (striping) management. The plurality of storage controllers (also referred to herein as RAID controllers) transmit cache requests to the central cache controller. The central cache controller performs all operations related to storing supplied data in cache memory as well as posting such cached data to the storage array as required.

Abstract: Apparatus and methods which allow multiple storage controllers sharing access to common data storage devices in a data storage subsystem to access a centralized intelligent cache. The intelligent central cache provides substantial processing for storage management functions. In particular, the central cache of the present invention performs RAID management functions on behalf of the plurality of storage controllers including, for example, redundancy information (parity) generation and checking as well as AID geometry (striping) management. The plurality of storage controllers (also referred to herein as RAID controllers) transmit cache requests to the central cache controllers. The central cache controllers performs all operations related to storing supplied data in cache memory as well as posting such cached data to the storage array as required.

Abstract: The present invention retrieves data across independent computer nodes of a server cluster by providing for I/O shipping of block level requests to peer intelligent host-bus adapters (hereinafter referred to as HBA). This peer-to-peer distribution of block I/O requests is transparent to the host. The HBA has the intelligence to decide whether to satisfy a block I/O request locally or remotely. Each HBA driver utilizes the I2O protocol, which allows peer-to-peer communication independent of the operating system or hardware of the underlying network. In a first embodiment of the present invention, local and remote storage channels, within a node, are supported by a single HBA. In a second embodiment of the present invention, local storage channels, within a node, are supported by one HBA, and the remote storage channel, within a node, is supported by a separate HBA.

Abstract: A DMA controller operable within a host adapter which automatically transmits replies to an attached host system to thereby reduce overhead processing in the I/O processor of the host adapter. The DMA controller is preferably operable to perform DMA transfers in accordance with one or more scatter/gather lists descriptive of the desired data transfer. A flag bit associated with and/or contained in entries of the scatter/gather list signifies the need to transmit a reply message to the host system. The requisite reply message is transmitted to the host system by the DMA controller following the DMA transfer of the block defined by the scatter/gather list entry containing the indicator. The reply message content is determined in accordance with information associated with and/or contained in the subsequent entry of the scatter/gather list. The subsequent scatter/gather list entry includes a reference to the reply message content and a reference to the destination location to which the reply is transmitted.

Abstract: A RAID controller integrated into a single chip. The RAID controller chip includes a general purpose RISC processor, memory interface logic, a host CPU PCI bus, at least one back-end I/O interface channel, at least one direct memory access (DMA) channel, and a RAID parity assist (RPA) circuit. The RAID chip enables higher integration of RAID functions within a printed circuit board and in particular enables RAID function integration directly on a personal computer or workstation motherboard. The back-end I/O interface channel is preferably dual SCSI channels. The RAID chip is operable in either of two modes. In a first mode, the chip provides pass through from the host CPU interface directly to the dual SCSI channels. This first mode of operation, a SCSI pass-through mode, allows use of the chip for non-RAID storage applications and enables low level manipulation of the disk array in RAID applications of the chip.

Abstract: A cache memory control architecture within a RAID storage subsystem which simplifies the migration and porting of existing ("legacy") control methods and structures to newer high performance cache memory designs. A centralized high speed cache memory is controlled by a main memory controller circuit. One or more bus bridge circuits adapt the signals from the bus architecture used by the legacy systems to the high speed cache memory. The bus bridge circuits each adapt, for example, a PCI bus used for a particular cache access purpose to the signal standards of an intermediate shared memory bus. The main memory controller circuit adapts the signals applied to the intermediate shared memory bus to the high speed cache memory bus. The hierarchical bus architecture permits older "legacy" control methods and structures to be easily adapted to newer cache memory architectures.

Abstract: A method for transferring data in a controller is disclosed which includes the steps of providing a processor having an internal first bus, providing a second bus, connecting a memory device to the second bus, connecting a disk drive to the second bus, transferring first data between the memory device and the processor across the first and second buses, and transferring second data between the memory device and the disk drive across the second bus. A disk array controller architecture is also disclosed.

Abstract: A method for transferring data in a controller having a processor and a controller support device, with the controller connected to a host device and a disk drive. The method includes the steps of providing the controller with a first bus and a second bus, connecting a first bus between the disk drive and the host device, connecting a second bus between the processor and the controller support device, transferring first data between the disk drive and the host device across the first bus, and transferring second data between the processor and the controller support device across the second bus without consuming any portion of the bandwidth of the first bus. A controller architecture is also disclosed.

Abstract: A transfer memory backup system for a RAID level 5 disk array storage system which includes a transfer buffer, wherein write data received by the array is written into a transfer buffer, and a write complete status signal generated, prior to the write data being written to the disk drives within the array. The transfer memory backup system includes a low power, industry standard PCMCIA (Personal Computer Memory Card International Association) device along with a small, temporary voltage source made up of a small rechargeable battery or a high capacitance gold capacitor. Upon the detection of a disk array storage system failure, low power logic provides continuous refresh for the transfer buffer as well as power to the components included in the transfer memory backup system upon a disk array storage system failure. A low power CMOS microprocessor with self contained microcode (mask programmable ROM) controls the transfer of data from the transfer buffer to removable storage medium within the PCMCIA device.

Abstract: A disk array controller providing a variable configuration data path between the host system and the individual disk drives within a disk array and parity and error correcting code generation and checking. The controller includes host interface logic for converting data received from the host system via a 16 or 32-bit SCSI bus to 16, 32 or 64-bit data words multiplexed across one, two or four 16-bit buffer busses, and for converting data received from the buffer busses to the proper form for transmission to the host system. A bus switch, including an exclusive-OR circuit for generating parity information, is connected between the buffer busses and six disk drive busses for directing the transfer of data and parity information between selected buffer and drive busses. The controller further includes a storage buffer connected to the buffer busses to provide temporary storage of data and parity information.

Abstract: A circuit for use with a SCSI interface for controlling synchronous data transfers into an attached FIFO memory. The circuit uses a comparator to keep track of the number of FIFO locations available by starting with a threshold value, which represents the locations available initially, and comparing the net number of FIFO locations filled to the threshold value. The net number of FIFO locations filled is kept by a counter which counts the difference between the words transferred into the FIFO and the words transferred out of the FIFO. The threshold value is an adjusted offset value if the SCSI interface is operating in INITIATOR mode, and the FIFO size if the SCSI interface is operating in TARGET mode. When the comparator determines that the FIFO is filled, it pauses the current synchronous message by withholding an ACK in the INITIATOR mode or a REQ in the TARGET mode.

Abstract: The present invention couples a disk drive to a small computer system interface bus by means of two buffers connected between a buffer-in bus and a buffer-out bus to allow data to be read out from a first filled buffer onto the buffer-out bus, while simultaneously permitting a filling of the second buffer from the buffer-in bus. When the second buffer is full and the first buffer is empty, the second buffer may be read while the first buffer is again filled. Toggling between the two buffers continues until the required data transfer is complete.

Abstract: The present circuit incorporates a latch which latches an asynchronous input signal and provides a latched output signal to the first stage of a two stage synchronizer. An AND gate receives the latched output signal and the output from the first stage such that the output signal from the AND gate follows the output of the first synchronizer and is presented as an input to a second stage of the two stage synchronizer. The second stage is clocked, as is the first stage, with the system clock signal to provide the synchronized output signal. An asynchronous reset of the latch causes the output of the AND gate to go low which in turn causes the output of the second stage to go low asynchronously.

Abstract: A method of operating a finite state machine to control the sequence of operations for transferring data through two or more rotating data buffers. The data transfer is either from a SCSI bus to a disk memory system, or from a disk memory system to a SCSI bus. The finite state machine is self-sequencing after initiation from an external source. An apparatus for implementing the method is also presented.