CONCURRENCY CONTROL IN A FILE SYSTEM SHARED BY APPLICATION HOSTS

• US 20110010390A1
• Filed: 07/13/2009
• Published: 01/13/2011
• Est. Priority Date: 07/13/2009
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: TAN, Yuen-Lin, RAJAGOPAL, Haripriya, VAGHANI, Satyam
• Granted Patent: US 8,521,686 B2
• Time in Patent Office: Days
• US Class Current: 707/770
• CPC Class Codes: G06F 16/1767 Concurrency control, e.g. optimistic or pessimistic approaches
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A manager program for managing virtual machines includes a process which receives a notification message indicating an occurrence of an event affecting a data storage unit in a data storage system that supports a shared file system. The notification message might have come from a virtual machine host or resulted from a hardware reconfiguration. The manager program then determines whether another virtual machine host is sharing the data storage unit. The manager program might make this determination by polling each of the virtual machine hosts it manages or by checking information previously collected and stored in a database. If another virtual machine host is sharing the data storage unit, the manager program sends a refresh message to that virtual machine host that causes the virtual machine host to update information relating to the data storage unit in a cache associated with the virtual machine host.

Claims

1. A method, comprising:

receiving a notification message from a first host indicating an occurrence of an event affecting a data storage unit in a data storage system that supports a shared file system;

determining whether a second host is sharing the data storage unit; and

sending a refresh message to the second host that causes the second host to update information relating to the data storage unit in a cache associated with the first host and the second host, if the first host and the second host are sharing the data storage unit, wherein each operation of the method is executed by a processor.

2. A method as in claim 1, wherein the notification message indicates that the first host performed an operation on the data storage unit that resulted in the data storage unit receiving a file system.

3. A method as in claim 1, wherein the operation at least one of creating a file system, upgrading a file system, growing a file system, spanning a data storage unit that was previously unused, and removing a data storage unit.

4. A method as in claim 1, wherein the event is hardware reconfiguration such as addition, removal or failure related to the data storage unit.

5. A method as in claim 1, wherein the refresh message causes the first host to update information relating to all of data storage units in the data storage system.

6. A method as in claim 1, wherein the refresh message causes the first host to update information relating to only the affected data storage unit.

7. A method as in claim 1, wherein the determining operation includes sending a polling message querying the first host as to whether the first host is sharing the data storage unit and receiving a response message from the first host indicating that the first host is sharing the data storage unit.

8. A method as in claim 7, wherein the indication in the response message is stored in a database for subsequent access.

9. A method as is claim 1, further comprising the operation of displaying one or more views in a graphical user interface that include the updated information relating to the data storage unit.

10. Software encoded in one or more storage media and when executed by a processor operable to:

receive a notification message indicating an occurrence of an event affecting a data storage unit in a data storage system that supports a shared file system;

determine whether a host is sharing the data storage unit; and

send a refresh message that causes the host to update information relating to the data storage unit in a cache associated with the host, if the host is sharing the data storage unit.

11. Software as in claim 10, wherein the notification message is from another host which shares the data storage unit and wherein the notification message indicates that the other host performed an operation on the data storage unit that resulted in the data storage unit receiving a file system.

12. Software as in claim 11, wherein the operation is selected from the group of operations consisting of creating a file system, upgrading a file system, growing a file system, and spanning a data storage unit that was previously unused.

13. Software as in claim 10, wherein the event is hardware failure related to the data storage unit.

14. Software as in claim 10, wherein the refresh message causes the host to update information relating to all of data storage units in the data storage system.

15. Software as in claim 10, wherein the refresh message causes the host to update information relating to only the affected data storage unit.

16. Software as in claim 10, wherein the determination as to whether a host is sharing the data storage unit includes sending a polling message querying the host as to whether the host is sharing the data storage unit and receiving a response message from the host indicating that the host is sharing the data storage unit.

17. Software as in claim 16, wherein the indication in the response message is stored in a database for subsequent access.

18. A method, comprising:

receiving a notification message indicating an occurrence of an event affecting a data storage unit in a data storage system that supports a shared file system;

determining whether an application program is sharing the data storage unit; and

sending a refresh message to the application program that causes the application program to update information relating to the data storage unit in a cache associated with the application program, if the application program is sharing the data storage unit, wherein each operation of the method is executed by a processor.

19. A method as in claim 18, wherein the notification message is from another application program which shares the data storage unit and wherein the notification message indicates that the other host performed an operation on the data storage unit that resulted in the data storage unit receiving a file system.

20. A method as in claim 18, wherein the event is hardware failure related to the data storage unit.