System for physical storage architecture providing simultaneous access to common file by storing update data in update partitions and merging desired updates into common partition

• US 5,850,522 A
• Filed: 04/10/1996
• Issued: 12/15/1998
• Est. Priority Date: 02/03/1995
• Status: Expired due to Term

• Current Assignee: LJM Software, Inc.
• Original Assignee: Dex Information Systems, Inc.
• Inventors: Wlaschin, Scott
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Ton, David
• Application Number:
  US08/633,839
• Time in Patent Office: 979 Days
• Field of Search: 707/10, 707/8, 395/500, 395/200.45, 395/651, 711/153, 711/173
• US Class Current: 709/215
• CPC Class Codes: G06F 16/176 Support for shared access to files; File sharing support

Abstract

A distributed storage system provides a method and apparatus for storing, retrieving, and sharing data items across multiple physical storage devices that may not always be connected with one another. The distributed storage system of the present invention comprises one or more `partitions` on distinct storage devices, with each partition comprising of a group of associated data files. Partitions can be of various types. Journal partitions may be written to by a user and contain the user'"'"'s updates to shared files. In the preferred embodiment, journal partitions reside on a storage device associated with a client computer in a client-server architecture. Other types of partitions, library and archive partitions, may reside on storage devices associated with a server computer in a client-server architecture. The files on the journal partitions of the various clients may, at various times, be merged into a consolidation file or a file resident within the library partition. If two or more clients attempt to update or alter data related to the same file, the system resolves the conflict between the clients to determine which updates, if any, should be stored in the library partition. The merge operation may occur at various time intervals or be event driven. The archive partition stores files from the library partition.

Claims

1. A method for providing simultaneous access to a common file on a computer network comprising at least one computer, said method including the steps of:

partitioning a first memory on said at least one computer to provide a first user with a first partition to store updates to files corresponding to said first user, said first memory at least partially inaccessible to a second user;

partitioning a second memory on said at least one computer to provide said second user with a second partition to store updates to files corresponding to said second user, said second memory at least partially inaccessible to said first user;

partitioning a third memory on said at least one computer to store selected updates from said first and second user partitions to create a first common partition such that said first and second users have associated partition chains comprising said first and second partitions, respectively, and said common partition;

storing first user update data in said first partition while maintaining common data unchanged, said first user update data corresponding to chases to said common data file by said first user;

storing second user update data in said second partition while maintaining common data unchanged, said second user update date corresponding to changes to said common data file by said second user;

selectively storing desired updates from said first and second partitions in said first common partition; and

providing each of said first and second users access to said first common partition.

2. The method of claim 1 wherein said first and second partitions and said first common partition reside on different computers.

3. The method of claim 1 wherein said first common partition comprises a library partition.

4. The method of claim 1 further comprising the steps of:

defining a second common partition accessible to said first and said second users; and

linking said second common partition to said first and second user partition chains.

5. The method of claim 4 wherein said second common partition comprises an archive partition.

6. The method of claim 5 further comprising the step of:

merging selected data updates from said first common partition to said second common partition.

7. The method of claim 1 further comprising the steps of:

defining a new partition based upon a subset of said first partition; and

linking said new partition to said second user'"'"'s partition chain.

8. The method of claim 7 wherein said new partition includes an update or an annotation to a CD-ROM.

9. The method of claim 1 wherein the step of merging selected first and or second update data from said first and or second partitions respectively into said first common partition further comprises:

selecting between conflicting data of said first and second update data in accordance with specified criteria for replacing said common data in said same data field, in the event that a first user selected data field and a second user selected data field are the same data field in said first common partition.

10. A method for providing simultaneous access to a common file on a computer network, said network including at least two local computers and at least one remote computer coupled to each of said at least two local computers, said method including the steps of:

partitioning memories on said local computers into journal partitions;

storing updates to said file, while maintaining common data unchanged, in user update files on respective said journal partitions;

partitioning memories on said local computers into local library partitions;

storing information from respective user update files of said journal partitions while maintaining common data unchanged;

updating at least one of said user update files while its associated computer is disconnected from said remote computer;

transmitting said updates from said associated computer to said remote computer after said remote computer is reconnected with said associated computer;

receiving updates on said remote computer from each of said at least two local computers;

partitioning a memory on said remote computer into a remote partition that stores said updates from said at least two local computers; and

merging said updates from said at least two local computers into said remote partition.

11. A storage system for a computer network simultaneously accessible by at least a first and second user, comprising:

at least one physical storage device,

a common partition defined in sa id a t least one physical storage device storing common data which is accessible to said first and second users;

a first update partition defined in said at least one physical storage device storing first update data from said first user representing changes to said common data in first user selected data fields in said common partition while maintaining common data unchanged, said first update data in said first partition is at least partially inaccessible to said second user;

a second update partition defined in said at least one physical storage device storing second update data provided by said second user representing changes to the common data in second user selected data fields in said common partition while maintaining common data unchanged, said second update data in said second partition is at least partially inaccessible to said first user;

means for linking two or more partitions together to form partition chains; and

means for selectively merging said first and second update data in to said common partition at a desired time so as to replace the common data in said first and second user selected data fields with said first and second update data.

12. The device of claim 11 wherein said update data and said common data is masked from visibility by subsequent partitions in said partition chains.

13. A method for providing simultaneous access by at least a first and second user to a common data file on a computer network comprising at least one physical storage device, said method including the steps of:

defining a first common partition on said at least one physical storage device accessible to said first and said second users;

defining a first update partition on said at least one physical storage device, said first update partition accessible to said first user and at least partially inaccessible to said second user;

forming a first user partition chain by linking said first common partition and said first update partition;

storing first user update data in said first update partition while maintaining common data unchanged, said first user update data corresponding to changes to said common data file by said first user;

is defining a second update partition on said at least one physical storage device, said second update partition accessible to said second user and at least partially inaccessible to said first user;

forming a second user partition chain by linking said first common partition and said second update partition;

storing second user update data in said second update partition while maintaining common data unchanged, said second user update data corresponding to changes to said common data file by said second user;

merging selected first and or second update data from said first and or second update partitions respectively into said first common partition.