This patent description was copied from http://www.delphion.com/ , on 1 August 2002.

Title: US5668943: Virtual shared disks with application transparent recovery

Country: US United States of America
Inventor: Attanasio, Clement Richard ; Peekskill, NY
Butrico, Maria Angela ; Blauvelt, NY
Peterson, James Lyle ; Austin, TX
Polyzois, Christos Alkiviadis ; White Plains, NY
Smith, Stephen Edwin ; Mahopac, NY
View Images 11 pages
Assignee: International Business Machines Corporation , Armonk, NY
other patents from INTERNATIONAL BUSINESS MACHINES CORPORATION (approx. 33,182)
Published/Filed: Sept. 16, 1997 / May 24, 1996
Application Number: US1996000653098

IPC Code: G06F 11/00;

ECLA Code: G06F11/14A8C; G06F11/20L8F;

U.S. Class: Current: 714/007 ; 714/004 ; 714/015 ; 714/043 ;
Original: 395/182.05 ; 395/182.02 ; 395/182.13 ; 395/183.19 ;
Field of Search: 395/182.02,182.03,182.04,182.05,183.18,183.19,182.08,200.08,182.13

Priority Number:
May 24, 1996   US1996000653098
Oct. 31, 1994   US1994000332157

Abstract: A system and method for recovering from failures in the disk access path of a clustered computing system. Each node of the clustered computing system is provided with proxy software for handling physical disk access requests from applications executing on the node and for directing the disk access requests to an appropriate server to which the disk is physically attached. The proxy software on each node maintains state information for all pending requests originating from that node. In response to detection of a failure along the disk access path, the proxy software on all of the nodes directs all further requests for disk access to a secondary node physically attached to the same disk.
Attorney, Agent or Firm: Ludwin, Richard M. ; Jordan, Kevin M. ;
Primary/Assistant Examiners: Beausoliel, Jr., Robert W. ; Palys, Joseph E.
Related Applications:
Application Number ApplDate Patent Pub. Date  Title
US1994000332157 1994-10-31       


Parent Case: This is a continuation, of application Ser. No. 08/332,157, filed Oct. 31, 1994, now abandoned.
Designated Country: DE FR GB 
First Claim: Show all 9 claims

We claim:

1. A clustered multi-processing system comprising:

  • at least three interconnected nodes wherein less than all nodes are server nodes, each node including a memory;
  • a multi-ported disk having at least a primary tail physically attached to a primary server node and a secondary tail physically attached to a secondary server node;
  • a disk access request mechanism, coupled to the nodes, for communicating a disk access request from an originating node to a server node physically attached to the disk along one of at least a primary disk access path and a secondary disk access path defined between the originating node, the server nodes and the disk;
  • a failure detection mechanism, coupled to the nodes, for detecting failures along one of the primary disk access path and the secondary disk access path; and,
  • proxy logic stored in the memory on each of the nodes and coupled to the failure detection mechanism, for redirecting subsequent disk access requests along a non-failing disk access path to the disk, when a failure is detected;
  • said proxy logic comprising a two-phase commit protocol including:
    • a coordinator node being adapted for broadcasting a suspend message to participant nodes to suspend access to a failed disk access path and waiting for an acknowledge message from all participant nodes;
    • each participant node receiving the suspend message being adapted for suspending said access to the failed disk access path, sending the acknowledge message to the coordinator node confirming suspension of said access to the failed disk access path, and waiting for a resume message from the coordinator node;
    • the coordinator node being further adapted for sending the resume message upon receipt of the acknowledge message from said all participant nodes; and
    • said each participant node being further adapted for redirecting said subsequent disk access requests along the non-failing disk access path to the disk, upon receipt of the resume message.
U.S. References:   |  Forward references (53)   |  Backward references (8)   |  

Patent   Pub.Date   Inventor Assignee    Title
  US5155845 1992-10 Beal et al.  Storage Technology Corporation Data storage system for providing redundant copies of data on different disk drives
  US5193086 1993-03 Satomi et al.  Hitachi, Ltd. Network system having a line switching function
  US5197148 1993-03 Blount et al.  International Business Machines Corporation Method for maintaining data availability after component failure included denying access to others while completing by one of the microprocessor systems an atomic transaction changing a portion of the multiple copies of data
  US5202887 1993-04 Ueno et al.  Hitachi, Ltd. Access control method for shared duplex direct access storage device and computer system therefor
  US5212785 1993-05 Powers et al.  Micro Technology, Inc. Apparatus and method for controlling data flow between a computer and memory devices
  US5218601 1993-06 Chujo et al.  Fujitsu Limited Method for searching for alternate path in communication network
  US5226037 1993-07 Satomi et al.  Hitachi, Ltd. Line switching system
  US5226151 1993-07 Takida et al.  Fujitsu Limited Emergency resumption processing apparatus for an information processing system
Foreign References: None
Other Abstract Info: DERABS G1996-211279
Other References:
  • A. M. Gheith and J. L. Peterson, "Shared Virtual Disk for a Cluster of Processors with Separate I/O Devices and Shared Memory", IBM Technical Disclosure Bulletin, vol. 36, No. 06B, pp. 375-377, Jun. 1993.
  • H. Bardsley III et al., "Dynamic Storage Susbsystem Path Switching", IBM Technical Disclosure Bulletin, vol. 32, No. 11, pp. 168-169, Apr. 1990.
  • J. C. O'Quin et al., "Takeover Scheme for Control of Shared Disks", IBM Technical Disclosure Bulletin, vol. 32, No. 2, pp. 378-380, Jul. 1989.