2.
    发明专利
    未知

    公开(公告)号:DE69032534D1

    公开(公告)日:1998-09-10

    申请号:DE69032534

    申请日:1990-04-10

    Applicant: IBM

    Abstract: The disclosed arrangement controls how client data processing systems in a distributed networking environment can efficiently extend files and write into regions of the files previously unoccupied by data. The server data processing system manages the distributed allocation of new file blocks by sending nascent zeros in addition to real bytes that have been requested by the client data processing system. Nascent zeros are logically zero bytes that have never been stored to or written to, and may be outside the current extent of the file. The server determines whether or not this additional range of nascent zeros will be sent to a client depending upon the amount of physical storage available at the server, and whether or not other client data processing systems require access to this range of blocks. Likewise, the client data processing system has the option of writing to this additional range of nascent zeros. By writing to the additional range of nascent zeros, a client data processing system can minimise the network traffic overhead used in sending messages to the server data processing system requesting a range of bytes.

    FILE EXTENSION BY CLIENTS IN A DISTRIBUTED DATA PROCESSING SYSTEM

    公开(公告)号:AU627567B2

    公开(公告)日:1992-08-27

    申请号:AU5362490

    申请日:1990-04-17

    Applicant: IBM

    Abstract: The disclosed arrangement controls how client data processing systems in a distributed networking environment can efficiently extend files and write into regions of the files previously unoccupied by data. The server data processing system manages the distributed allocation of new file blocks by sending nascent zeros in addition to real bytes that have been requested by the client data processing system. Nascent zeros are logically zero bytes that have never been stored to or written to, and may be outside the current extent of the file. The server determines whether or not this additional range of nascent zeros will be sent to a client depending upon the amount of physical storage available at the server, and whether or not other client data processing systems require access to this range of blocks. Likewise, the client data processing system has the option of writing to this additional range of nascent zeros. By writing to the additional range of nascent zeros, a client data processing system can minimise the network traffic overhead used in sending messages to the server data processing system requesting a range of bytes.

    4.
    发明专利
    未知

    公开(公告)号:DE69032534T2

    公开(公告)日:1999-04-22

    申请号:DE69032534

    申请日:1990-04-10

    Applicant: IBM

    Abstract: The disclosed arrangement controls how client data processing systems in a distributed networking environment can efficiently extend files and write into regions of the files previously unoccupied by data. The server data processing system manages the distributed allocation of new file blocks by sending nascent zeros in addition to real bytes that have been requested by the client data processing system. Nascent zeros are logically zero bytes that have never been stored to or written to, and may be outside the current extent of the file. The server determines whether or not this additional range of nascent zeros will be sent to a client depending upon the amount of physical storage available at the server, and whether or not other client data processing systems require access to this range of blocks. Likewise, the client data processing system has the option of writing to this additional range of nascent zeros. By writing to the additional range of nascent zeros, a client data processing system can minimise the network traffic overhead used in sending messages to the server data processing system requesting a range of bytes.

    5.
    发明专利
    未知

    公开(公告)号:DE69031926T2

    公开(公告)日:1998-08-13

    申请号:DE69031926

    申请日:1990-04-10

    Applicant: IBM

    Abstract: The disclosed arrangement maintains the latest file attributes such as file size, modify time, and access time, at the server data processing system in a distributed data processing system. The server data processing system combines information requested from the client data processing system that has permission to write to the file with information periodically received from other client data processing systems that may be extending the same file by mapping the file into their own virtual address space. In this way, the server can maintain the latest file size attribute even when some clients are extending the file through system calls and other clients are extending the file through mapped access. To maintain a latest modify time and access time, the server keeps a modify count and access count. The client data processing systems periodically send to the server data processing the modify count and access count that have been incremented whenever the client data processing system modifies and accesses the file. The server data processing system compares the counts at the server with the counts received from the clients to determine a latest corresponding modify time and access time.

    9.
    发明专利
    未知

    公开(公告)号:DE3854384D1

    公开(公告)日:1995-10-05

    申请号:DE3854384

    申请日:1988-11-09

    Applicant: IBM

    Abstract: A method for maintaining the overall system availability of a multi-processor data processing system in the event of a failure at one of a plurality of independent failure points. The system includes a plurality of virtual memory type processor units, each of which includes an interactive terminal, and a main memory which is connected to a secondary storage device which is also shared by the main memory of one of the other processor units. The main memories of the two units are also interconnected to provide a shared virtual memory system. Both processor units employ the same operating system and share the same virtual address space for storing information. The interactive terminal of each processor unit is connected to the other processor unit. Failure points include the terminals, the processor units, the communication links, and the various software components that are employed by the system. System availability is maintained by managing the storage of selected information at pre-established precise points in the processing operation. Identical operating system data structures that are stored in each processor unit are updated with the results of certain identified data processing transactions which have affected information required for succeeding processing operations in manner to insure that either identical updates occur or no update occurs. The arrangement ensures that any changes that might have occurred in the information stored in the data structure prior to the end of an aborted transaction is returned to the initial state to permit the transaction to be retried whenever the path of the failure can be bypassed.

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