Parallel metadata service in storage area network environment

• US 20030220974A1
• Filed: 05/23/2002
• Published: 11/27/2003
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schmuck, Frank B., Haskin, Roger L., Curran, Robert J., Wang-Knop, Kuei-Yu
• Granted Patent: US 8,140,622 B2
• Time in Patent Office: Days
• US Class Current: 709/205
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files

Abstract

A method for data access in a multinode, shared storage data processing environment is provided by enhancing the file locking mechanism structure so as to permit nodes not normally designated as metadata controller nodes to fulfill that function for limited times thus at least temporarily eliminating the need for continual node-to-node coordination. This is particularly advantageous in the access and transfer of large files such as video files or files containing complex visualization data.

Claims

1. A method for accessing data in a shared storage environment, said method comprising the steps of:

establishing metadata file system control structures on at least some of a plurality of data processing nodes which share access to a set of data storage devices;

sending a request to a first node which is one of said plurality of nodes to grant access to a file which is resident within said set of storage devices, said request being sent from a second node which does not belong to said plurality of nodes;

providing a lock for use by said first node, in response to said request, wherein said lock includes permission for said first node to allow said second node to directly access said file for a limited period of time;

transferring metadata information pertaining to said file to said second node; and

accessing said file during said limited time from said second node using said transferred metadata information.

2. The method of claim 1 in which said shared storage environment includes a storage area network.

3. The method of claim 1 in which said request is transmitted over a Local Area Network.

4. The method of claim 1 in which said lock further includes an indication that the granting of said permission is conditioned on coordination with a third node which also contains metadata for accessing said file.

5. The method of claim 1 further including the step of renewing said grant of access during said limited time period.

6. A method for accessing data in a multinode, shared storage environment, said method comprising the step of:

granting permission to access a file resident within said shared storage environment through the use of a file locking mechanism in which a node acting as a metadata controller node temporarily enables another node to access a specific file.

7. The method of claim 6 in which said node acting as a metadata controller node is one of a plurality of nodes possessing metadata controller capabilities which are able to provide such capabilities in the event of node failure.

8. A multinode data processing system comprising:

a plurality of data processing nodes;

a set of storage devices;

storage means within at least one of said nodes containing program code for granting permission to access a file resident within said set of storage devices through the use of a file locking mechanism in which said one node acts as a metadata controller node so as to temporarily enable another node to access a specific file.

9. A program product comprising a machine readable medium containing program code, for use in a multinode data processing system, for granting permission to access a file resident within a set of storage devices accessible to said nodes through the use of a file locking mechanism in which one of said nodes acts as a metadata controller node so as to temporarily enable another node to access a specific file.