公开(公告)号：GB2376612B

公开(公告)日：2004-06-09

申请号：GB0114614

申请日：2001-06-15

Applicant: IBM

Inventor： CASHMAN PAUL NICHOLAS ,  NICHOLSON ROBERT BRUCE ,  MADDOCK ROBERT FRANK ,  BEER REGINALD ,  MORRIS NEIL ,  JUDD IAN DAVID ,  WHYTE BARRY DOUGLAS ,  HOOTON PAUL

IPC: H04L12/24 ,  H04L12/437 ,  H04L12/42 ,  H04L12/26

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 ).

公开(公告)号：GB2365545B

公开(公告)日：2004-06-02

申请号：GB9930282

申请日：1999-12-23

Applicant: IBM

Inventor： FUENTE CARLOS FRANCISCO ,  BUTTERWORTH HENRY ESMOND ,  NICHOLSON ROBERT BRUCE

IPC: G06F3/06 ,  G06F13/14 ,  G06F15/16

Abstract: A data processing system comprises a master processor ( 10 ), a slave processor ( 30 ), a memory ( 50 ), and a bus subsystem ( 20 ) interconnecting the master processor ( 10 ), the slave processor ( 30 ), and the memory ( 50 ). The master processor ( 10 ) is configured to generate, in response to a memory access instruction, a read request comprising a read command for execution by the slave processor ( 30 ) to read data stored in a location in the memory ( 50 ) specified by the memory access instruction, and to write the read request to the slave processor ( 30 ) via the bus subsystem ( 20 ). The slave processor ( 30 ) is configured to execute the read command received in the read request from the master processor ( 10 ) to obtain the data stored at the specified location in the memory ( 50 ) and to write the data thus obtained to the master processor ( 10 ) via the bus subsystem ( 20 ).

公开(公告)号：GB2384405A

公开(公告)日：2003-07-23

申请号：GB0201212

申请日：2002-01-19

Applicant: IBM

Inventor： BEER REGINALD ,  CASHMAN PAUL NICHOLAS ,  HOOTON PAUL ,  MORRIS NEIL ,  MADDOCK ROBERT FRANK ,  NICHOLSON ROBERT BRUCE

IPC: H04L12/42 ,  H04L12/423 ,  H04L12/437

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 has a plurality of devices each device having at least one port on the loop network. The method includes determining which ports are populated with devices for which the unique port name (WWPN) is not known 302. The populated ports are then all bypassed 303 and a mode is entered on the loop network in which idle frames are transmitted around the loop network. 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.

公开(公告)号：GB2377144A

公开(公告)日：2002-12-31

申请号：GB0117092

申请日：2001-07-13

Applicant: IBM

Inventor： BEER REGINALD ,  CASHMAN PAUL NICHOLAS ,  JUDD IAN DAVID ,  HOOTON PAUL ,  MADDOCK ROBERT FRANK ,  MORRIS NEIL ,  NICHOLSON ROBERT BRUCE ,  WHYTE BARRY DOUGLAS

IPC: H04L12/437 ,  H04L45/28

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). The host means (402) may determine the physical topology of the ports (410) on the first and second loops (406, 408) such that when a failure is reported to the host means (402) by a port (432) on the first loop (406), the host means (402) instructs the bypassing of a port (434) in a specific relationship to the reporting port (432) on the first loop (434). The host means (402) may instruct the bypassing of all ports (416) on the first loop (406) and subsequently selectively un-bypass ports (416) to ascertain the location of a faulty port or ports.

公开(公告)号：GB2369206A

公开(公告)日：2002-05-22

申请号：GB0028214

申请日：2000-11-18

Applicant: IBM

Inventor： BUTTERWORTH HENRY ESMOND ,  NICHOLSON ROBERT BRUCE

IPC: G06F11/07 ,  G06F11/10 ,  G06F11/14 ,  G06F12/08 ,  G06F13/00

Abstract: A program, system and method for rebuilding meta-data stored in a data storage system 104 having storage devices 106 in which segments of data are located; for example, a storage system in the form of a log structured array. Data is written in segments to the storage devices 106 from a plurality of flows 122 of data and each segment of data contains meta-data relating to that segment. The meta-data stored in the storage system 104 can be rebuilt in the event of a failure by scanning the meta-data in each segment. A first scan of the meta-data in each segment in the storage devices 106 identifies the last segment written from each flow 122 and these segments are excluded from the rebuilding process as they may contain incomplete or inconsistent information. A second scan of the meta-data in each segment in the storage devices 106 identifies any segments which do not contain any live data tracks and these segments are also excluded from the rebuilding process. The meta-data in the storage system 104 can then be rebuilt using the meta-data in the segments, excluding those segments identified.