Abstract: A method and apparatus for relating a device name to a physical location of a device (202) on a network is provided. The network may be a serial loop network, for example a Fibre Channel Arbitrated Loop network. The network includes a plurality of devices (202) on or connected to the network (201) and a control device (205) with control over at least one of the devices (202). Each device (202) has a check output (204) independent of the network (201) with connection means (206) to a control device (205). The method includes the step of sending a device name from the check output (204) of a device (202) to the control device (205). The check output (204) of a device (202) is also connected to an external indication means for indicating the failure of the device (202).

Abstract: A logic arrangement, method and computer program for reducing incidence of errors in a redundant path system during a process of attachment of a device to a running subsystem, comprises a control component for encapsulating the process of attachment of a device to a running subsystem; a disabling component for disabling a path interface; a testing component for testing for the presence of a usable data path across at least one further path interface; and an enabling component for enabling the at least one further path interface to accept communication with the device responsive to a positive outcome from the testing component; wherein the control component is adapted to permit operation after attachment of the device only if full redundancy is retained. A re-enabling component may re-enable any path interface or further path interface.

Abstract: A method and apparatus for recovery from faults in a loop network (500) is provided. The loop network (500) has a plurality of ports (520, 530, 532, 534) serially connected with means for bypassing the ports (520, 530, 532, 534) from the loop network (500). A control device (522, 524) is provided with bypass control over at least one of the ports (530, 532, 534). A host means (502) sends a command to the control device (522, 524) at regular intervals and the control device (522, 524) has a counter which restarts a time period at the receipt of each command. If the time period expires, the control device (522, 524) activates the means for bypassing all the ports (530, 532, 534) under its control. The loop network (500) may have two loops (516, 518) with at least some of the ports (520, 530, 532, 534) common to both loops (516, 518).

Abstract: A method and apparatus for relating a device name to a physical location of a device (202) on a network is provided. The network may be a serial loop network, for example a Fibre Channel Arbitrated Loop network. The network includes a plurality of devices (202) on or connected to the network (201) and a control device (205) with control over at least one of the devices (202). Each device (202) has a check output (204) independent of the network (201) with connection means (206) to a control device (205). The method includes the step of sending a device name from the check output (204) of a device (202) to the control device (205). The check output (204) of a device (202) is also connected to an external indication means for indicating the failure of the device (202).

Abstract: A method and apparatus for relating a device name to a physical location of a device (202) on a network is provided. The network may be a serial loop network, for example a Fibre Channel Arbitrated Loop network. The network includes a plurality of devices (202) on or connected to the network (201) and a control device (205) with control over at least one of the devices (202). Each device (202) has a check output (204) independent of the network (201) with connection means (206) to a control device (205). The method includes the step of sending a device name from the check output (204) of a device (202) to the control device (205). The check output (204) of a device (202) is also connected to an external indication means for indicating the failure of the device (202).

Abstract: A method and apparatus for detection of a port name in a loop network is provided, particularly a loop network in the form of a Fibre Channel Arbitrated Loop (FC-AL). The loop network (100) has a plurality of devices (120) each device (120) having at least one port (211, 212) on the loop network (100). The method includes determining which ports (211, 212) are populated with devices (120) for which the unique port name (WWPN) is not known. The populated ports are then all bypassed and a mode is entered on the loop network (100) in which idle frames are transmitted around the loop network (100). One port is un-bypassed at a time and the port name from the un-bypassed port is received and recorded. The port name is received from the un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.

Abstract: A method and apparatus for detection of a port name in a loop network is provided, particularly a loop network in the form of a Fibre Channel Arbitrated Loop (FC-AL). The loop network (100) has a plurality of devices (120) each device (120) having at least one port (211, 212) on the loop network (100). The method includes determining which ports (211, 212) are populated with devices (120) for which the unique port name (WWPN) is not known. The populated ports are then all bypassed and a mode is entered on the loop network (100) in which idle frames are transmitted around the loop network (100). One port is un-bypassed at a time and the port name from the un-bypassed port is received and recorded. The port name is received from the un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.

Abstract: A method and apparatus for recovery from faults in a loop network (500) is provided. The loop network (500) has a plurality of ports (520, 530, 532, 534) serially connected with means for bypassing the ports (520, 530, 532, 534) from the loop network (500). A control device (522, 524) is provided with bypass control over at least one of the ports (530, 532, 534). A host means (502) sends a command to the control device (522, 524) at regular intervals and the control device (522, 524) has a counter which restarts a time period at the receipt of each command. If the time period expires, the control device (522, 524) activates the means for bypassing all the ports (530, 532, 534) under its control. The loop network (500) may have two loops (516, 518) with at least some of the ports (520, 530, 532, 534) common to both loops (516, 518).

Abstract: A method and apparatus for recovery from faults in a loop network (400) is provided. The loop network (400) has a host means (402), a first loop and a second loop (406, 408), a plurality of ports (410) connected to each of the loops (406, 408) and a control device (414, 440) on or connected to each loop (406, 408) with bypass control over at least one of the ports (410) connected to the loop (406, 408). In the event of a failure on the first loop (406), the host means (402) instructs the bypassing of at least one port (410) on the first loop (406), the host means (402) sending the instructions via the control device (414, 440) on or connected to the second loop (408).

Abstract: A method and apparatus for recovery from faults in a loop network (500) is provided. The loop network (500) has a plurality of ports (520, 530, 532, 534) serially connected with means for bypassing the ports (520, 530, 532, 534) from the loop network (500). A control device (522, 524) is provided with bypass control over at least one of the ports (530, 532, 534). A host means (502) sends a command to the control device (522, 524) at regular intervals and the control device (522, 524) has a counter which restarts a time period at the receipt of each command. If the time period expires, the control device (522, 524) activates the means for bypassing all the ports (530, 532, 534) under its control. The loop network (500) may have two loops (516, 518) with at least some of the ports (520, 530, 532, 534) common to both loops (516, 518).

Abstract: A logic arrangement, method and computer program for reducing incidence of errors in a redundant path system during a process of attachment of a device to a running subsystem, comprises a control component for encapsulating the process of attachment of a device to a running subsystem; a disabling component for disabling a path interface; a testing component for testing for the presence of a usable data path across at least one further path interface; and an enabling component for enabling the at least one further path interface to accept communication with the device responsive to a positive outcome from the testing component; wherein the control component is adapted to permit operation after attachment of the device only if full redundancy is retained. A re-enabling component may re-enable any path interface or further path interface.

Abstract: A method and apparatus are provided for fault location in a loop network (100, 200, 400). The network system having a host port (214) for supplying and receiving data and a plurality of successively connected ports (201, 202, 203, 204, 205) through which data from the host port (214) is transferred. A counter (122) for each port records data transfers in which the amount of data received at a destination port is less than an expected amount of data. When a transfer with less than the expected amount of data is identified for a data flow between a sending port (201) and a destination port (214), the counters are incremented for each port (202, 203, 204, 205, 214) after the sending port up to and including the destination port. Analysing means determines a fault location in the network system from the distribution of counts in the counters (122).

Abstract: A disk drive arrangement (5) is provided for use in a disk drive enclosure having a number of such arrangements. The enclosure is arranged to provide enclosure services to the arrangement (5). Each arrangement (5) includes a disk drive (10) and an adapter (14) coupled between the disk drive (10) and a serial data connection 40 to a serial bus of the enclosure. The adapter includes serial to non-serial circuitry (30), such that the interface is coupled non-serially (15, 35) to the disk drive (10) and serially (40) to the bus. The bus is connected to an enclosure services processor in the enclosure. In this way enclosure services data may be exchanged between the processor and each arrangement (5) of the enclosure, thus providing enclosure services to each disk drive (10) of the enclosure with a serial bus.

Abstract: A method is provided for remotely controlling power to electronic devices. Each device includes two or more ports for receiving signals over the serial link. The method includes issuing a shutdown command from the host data processing system to selected one of the devices over the link and responsive to the receipt of a power-off command at a device, causing the device to enter a low power standby mode on cessation of signal activity at one of the device ports. On entering standby mode at a device, standby power is supplied in the device to allow the device to monitor the one or more device ports for incoming signals. In addition, transmission of signals via the one or more ports is ceased. On receipt of a signal at any of the one or more ports that was previously inactive, power is restored to the device.

Abstract: A method and apparatus for relating a device name to a physical location of a device (202) on a network is provided. The network may be a serial loop network, for example a Fibre Channel Arbitrated Loop network. The network includes a plurality of devices (202) on or connected to the network (201) and a control device (205) with control over at least one of the devices (202). Each device (202) has a check output (204) independent of the network (201) with connection means (206) to a control device (205). The method includes the step of sending a device name from the check output (204) of a device (202) to the control device (205). The check output (204) of a device (202) is also connected to an external indication means for indicating the failure of the device (202).

Abstract: A method and apparatus are provided for hard address conflict resolution for enclosures in a loop network (200). The loop network (200) has: a loop (202); a host means (201) on or connected to the loop (202); a plurality of devices (207) on or connected to the loop (202); and at least one enclosure containing one or more devices (207). Each device (207) has an address means. Each enclosure has an enclosure control device (208) with control over devices (207) in that enclosure. Each enclosure control device (208) has an address means. The method includes, at the start up of the loop network (200), setting the address means of the enclosure control devices (208) to a default value. Each device (207) is then entered in the loop (202) in a reset state in which only the enclosure control devices (208) and the host means (201) are active in the loop (202).

Abstract: A method and apparatus for detection of a port name in a loop network is provided, particularly a loop network in the form of a Fibre Channel Arbitrated Loop (FC-AL). The loop network (100) has a plurality of devices (120) each device (120) having at least one port (211, 212) on the loop network (100). The method includes determining which ports (211, 212) are populated with devices (120) for which the unique port name (WWPN) is not known. The populated ports are then all bypassed and a mode is entered on the loop network (100) in which idle frames are transmitted around the loop network (100). One port is un-bypassed at a time and the port name from the un-bypassed port is received and recorded. The port name is received from the un-bypassed port in a Loop Initialisation Select Master (LISM) frame transmitted by the un-bypassed port.

Abstract: A method and apparatus are provided for fault location in a loop network (100, 200, 400). The network system having a host port (214) for supplying and receiving data and a plurality of successively connected ports (201, 202, 203, 204, 205) through which data from the host port (214) is transferred. A counter (122) for each port records data transfers in which the amount of data received at a destination port is less than an expected amount of data; When a transfer with less than the expected amount of data is identified for a data flow between a sending port (201) and a destination port (214), the counters are incremented for each port (202, 203, 204, 205, 214) after the sending port up to and including the destination port. Analysing means determines a fault location in the network system from the distribution of counts in the counters (122).

Abstract: A method and apparatus for recovery from faults in a loop network (400) is provided. The loop network (400) has a host means (402), a first loop and a second loop (406, 408), a plurality of ports (410) connected to each of the loops (406, 408) and a control device (414, 440) on or connected to each loop (406, 408) with bypass control over at least one of the ports (410) connected to the loop (406, 408). In the event of a failure on the first loop (406), the host means (402) instructs the bypassing of at least one port (410) on the first loop (406), the host means (402) sending the instructions via the control device (414, 440) on or connected to the second loop (408).

Abstract: A method and apparatus for recovery from faults in a loop network (500) is provided. The loop network (500) has a plurality of ports (520, 530, 532, 534) serially connected with means for bypassing the ports (520, 530, 532, 534) from the loop network (500). A control device (522, 524) is provided with bypass control over at least one of the ports (530, 532, 534). A host means (502) sends a command to the control device (522, 524) at regular intervals and the control device (522, 524) has a counter which restarts a time period at the receipt of each command. If the time period expires, the control device (522, 524) activates the means for bypassing all the ports (530, 532, 534) under its control. The loop network (500) may have two loops (516, 518) with at least some of the ports (520, 530, 532, 534) common to both loops (516, 518).