Abstract: A multiplexing system couples a pair of input ports to a either a dual ported disk drive or a single ported disk drive. The system includes a multiplexer having the pair of first ports and a pair of second ports. The multiplexer is configurable to couple each one of the pair of first ports to a corresponding one of the pair of second ports when the pair of second ports are coupled to the dual ported disk drive and to couple both pair of first ports to a single one of the second ports when a single ported disk drive is coupled to said single one of the second ports.

Abstract: A data storage system has a chassis and a pair of printed circuit boards disposed in the chassis. Each one of the pair of printed circuit boards has disposed thereon a processor, a translator controlled by the processor, a SAS expander having a bidirectional front end port and multiple bidirectional backend ports, and an expansion port, and a SAS controller coupled between the translator and the expander. The system also has an interposer printed circuit board disposed in the chassis, and multiple multiplexers disposed on the interposer printed circuit board. Each one of the multiplexers has a pair of bidirectional front end ports and a pair of bidirectional back end ports. A first one of the pair of bidirectional front end ports is connected to a corresponding backend port of the SAS expander disposed on a first one of the pair of storage processor printed circuit boards.

Abstract: Described is a midplane-less storage system comprising an enclosure including a control board having an electrical connector attached thereto and a processing unit. The enclosure also includes a disk drive module with a disk drive for storing data and an adapter board electrically connected to the disk drive. The adapter board has a controller and an electrical connector that is mated to the electrical connector of the control board. A communication bus extends from the control board to the disk drive module through the mated electrical connectors. The processing unit of the control board communicates with the controller of the adapter board over the communication bus in accordance with a communication protocol in order to control operation of the disk drive.

Abstract: A data storage system having a first chassis, such first chassis having a pair of SAS expanders and a second chassis having a pair of SAS expanders. The first one of the pair of SAS expanders is connected to only an expansion port of a first one of a pair of signal processor printed circuit boards in the first one of the chassis. An expansion port of a second one of the pair of SAS expander is connected to only the expansion port of a second one of the pair of signal processor printed circuit boards in the second one of the chassis.

Abstract: Described is a storage system comprising a communication bus, a disk drive, a control board having a processing unit connected to the communication bus, and an adapter board in electrical communication with the disk drive. The adapter board has a controller connected to the communication bus. The controller receives instructions over the communication bus from the processing unit and communicates with the disk drive in response to the instructions. Optionally, the storage system has a midplane having a first connector connected to an electrical connector of the control board and a second connector connected to an electrical connector of the adapter board. Attached to opposite sides of the midplane, the first and second connectors are aligned with and electrically connected to each other through the midplane. An electrical signal transmitted between the control board and the adapter board passes directly through the midplane through the first and second midplane connectors.

Abstract: Single and dual ported devices are interfaced to a system via a 2:2 multiplexing device. The multiplexing device is coupled to two system ports and two device ports. The multiplexing device includes an active multiplexer coupled to the two system ports and a multiplexed port. The multiplexing device also includes bypass circuitry coupled to the two system ports and two bypass ports. In operation, when the multiplexing device is coupled via one of the device ports to a single ported device such as a single ported disk drive, the active multiplexer is activated and the bypass circuitry is deactivated and the multiplexed port is coupled to the device port. When the multiplexing device is coupled via both device ports to a dual ported device, the active multiplexer is deactivated and the bypass circuitry is activated and the bypass ports are coupled to the two device ports.

Abstract: Data storage equipment includes a first storage processor comprising a processing circuit and a collection of packaged integrated circuit devices which has a first set of ports and a second set of ports; a second storage processor; and an interconnect coupled between the first and second storage processors. The processing circuit of the first storage processor is adapted to execute as follows. The collection of packaged integrated circuit devices of the first storage processor is configured to provide (i) communications to a set of storage devices through the first set of ports of the collection of packaged integrated circuit devices and (ii) other communications to the second storage processor through the second set of ports of the collection of packaged integrated circuit devices. Communications is passed between the first storage processor and the set of storage devices through the first set of ports of the collection of packaged integrated circuit devices.

Abstract: A data storage system has a chassis and a pair of printed circuit boards disposed in the chassis. Each one of the pair of printed circuit boards has disposed thereon a processor, a translator controlled by the processor, a SAS expander having a bidirectional front end port and multiple bidirectional backend ports, and an expansion port, and a SAS controller coupled between the translator and the expander. The system also has an interposer printed circuit board disposed in the chassis, and multiple multiplexers disposed on the interposer printed circuit board. Each one of the multiplexers has a pair of bidirectional front end ports and a pair of bidirectional back end ports. A first one of the pair of bidirectional front end ports is connected to a corresponding backend port of the SAS expander disposed on a first one of the pair of storage processor printed circuit boards.

Abstract: High availability is provided in a storage system. The storage system includes a plurality of storage devices having reserved space, for example, for an operating system. Several power branches provide power to the storage devices. At least one of the storage devices is coupled to a first of the power branches, and at least one other storage device is coupled to another of the power branches. Furthermore, each of several devices has a unique address represented by a separate plurality of address bits. Logic produces intermediate bits, the number of intermediate bits being fewer than the number of address bits. The intermediate bits are used to drive the address bits. Some of the intermediate bits drive more than one address bit.

Abstract: Described are a storage system and method for detecting an intermittent loss of synchronization in communication signals received by an enclosure connected to a Fibre Channel loop. A control board produces a first signal representing a status of communication signals received by the control board. The first signal is in one of a plurality of logical states. A first logical state indicates that the status of the communication signals is invalid and a second logical state indicates that the status of the communication signals is valid. The control board includes a glitch-detection circuit that places a second signal in an asserted logical state when the first signal is in the first logical state during a time interval and holds the second signal at the asserted logical state when the first signal transitions from being in the first logical state to being in the second logical state during the time interval.

Abstract: First and second inputs are associated with a port. Logic produces indications to software to cause the first input and second input to appear as a single input to the software. The logic produces an indication that no signal is present on either the first input or the second input. When a port bypass controller is coupled to the port, the logic produces an indication that both the first and second inputs are bypassed. When the port bypass controller is coupled to a Fibre Channel arbitrated loop, the logic produces a first signal to control whether the first input is included on the Fibre Channel arbitrated loop or bypassed, and a second signal to control whether the second input is included in the Fibre Channel arbitrated loop or bypassed.

Abstract: Described are a system and method for reading revision information from an adapter board that interfaces a disk drive using request and grant signals. An adapter board is in electrical communication with a disk drive and with a control board. The adapter board has a controller with memory for storing data, with a request input terminal for receiving a request signal from the control board requesting access to a disk drive, with a grant output terminal for transmitting a grant signal to the control board granting access to the disk drive, and with a power down input terminal for receiving a power down signal to turn off power to the disk drive. The controller enters a read mode of operation in response to receiving a power down signal on the power down input terminal to enable the data stored in the memory to be read.

Abstract: Described is a storage system that operates with a diskless enclosure. The diskless enclosure comprises a communication port connected to an arbitrated loop, a plurality of storage ports each being connectable to a disk module, and port bypass control circuitry. The port bypass control circuitry includes retimer circuitry for retiming communication signals passing through the communication port to and from the arbitrated loop. The port bypass control circuitry forwards retimed communication signals to the arbitrated loop without any storage port of the plurality of storage ports having a disk module connected thereto.

Abstract: Described is an Advanced Technology Attachment (ATA) disk drive module for use in a data storage system having an enclosure with slots constructed to receive Fibre Channel disk drive modules. The ATA disk drive module comprises an ATA disk drive, an adapter board connected to the ATA disk drive, and a carrier assembly including spaced apart carrier sleds mounted to the ATA disk drive and to the adapter board. The spaced apart carrier sleds have mechanical dimensions that enable the carrier assembly to slide into an enclosure slot constructed to receive a Fibre Channel disk drive module. The adapter board provides an electrical interface and a mechanical interface between the ATA disk drive and a midplane of the enclosure when the carrier assembly is inserted in the enclosure slot and the ATA disk drive module is plugged into the midplane.

Abstract: Described are a storage system and a method for adapting to an incompatible disk drive that has been installed in a storage enclosure. An adapter board receives a signal from a control board that indicates a type of the control board. In response to the first signal, the adapter board determines whether the type of the control board is compatible with a disk drive that is installed in the storage enclosure. If the control board is of an incompatible type, the adapter board sends a signal to the control board that causes the control board to bypass the installed disk drive.

Abstract: Described are a system and method of detecting an improperly connected cable in a storage system. A system includes an enclosure having boards. Each board of the enclosure has a communications port that receives a message identifying a redundant backend network to which that board is connected. The enclosure determines whether the system has an improper cable connection by determining from the messages whether the boards are connected to the same redundant backend network.

Abstract: Described is a storage system comprising a communication bus, a disk drive, a control board having a processing unit connected to the communication bus, and an adapter board in electrical communication with the disk drive. The adapter board has a controller connected to the communication bus. The controller receives instructions over the communication bus from the processing unit and communicates with the disk drive in response to the instructions. Optionally, the storage system has a midplane having a first connector connected to an electrical connector of the control board and a second connector connected to an electrical connector of the adapter board. Attached to opposite sides of the midplane, the first and second connectors are aligned with and electrically connected to each other through the midplane. An electrical signal transmitted between the control board and the adapter board passes directly through the midplane through the first and second midplane connectors.

Abstract: Described are a storage system and method for detecting an intermittent loss of synchronization in communication signals received by an enclosure connected to a Fibre Channel loop. A control board produces a first signal representing a status of communication signals received by the control board. The first signal is in one of a plurality of logical states. A first logical state indicates that the status of the communication signals is invalid and a second logical state indicates that the status of the communication signals is valid. The control board includes a glitch-detection circuit that places a second signal in an asserted logical state when the first signal is in the first logical state during a time interval and holds the second signal at the asserted logical state when the first signal transitions from being in the first logical state to being in the second logical state during the time interval.

Abstract: Described are a storage system and a method for adapting to an incompatible disk drive that has been installed in a storage enclosure. An adapter board receives a signal from a control board that indicates a type of the control board. In response to the first signal, the adapter board determines whether the type of the control board is compatible with a disk drive that is installed in the storage enclosure. If the control board is of an incompatible type, the adapter board sends a signal to the control board that causes the control board to bypass the installed disk drive.

Abstract: Described are a system and method for reading revision information from an adapter board that interfaces a disk drive using request and grant signals. An adapter board is in electrical communication with a disk drive and with a control board. The adapter board has a controller with memory for storing data, with a request input terminal for receiving a request signal from the control board requesting access to a disk drive, with a grant output terminal for transmitting a grant signal to the control board granting access to the disk drive, and with a power down input terminal for receiving a power down signal to turn off power to the disk drive. The controller enters a read mode of operation in response to receiving a power down signal on the power down input terminal to enable the data stored in the memory to be read.