Granted Patent B2

US 7,590,775 · App. 10/912,722 · Granted Sep 15, 2009

Abstract

Claims (49)

1. A method for controlling utilisation of file storage by a plurality of processes, comprising:

establishing a controller daemon;

empirically determining a qualified bandwidth of the file storage;

the controller daemon maintaining a record of existing bandwidth reservations;

receiving at the controller daemon a request for a bandwidth reservation for access to the file storage by a process;

the controller daemon determining whether granting the request would result in a sum of bandwidth reservations which exceeds the qualified bandwidth; and

provided the qualified bandwidth would not be exceeded by granting the request, the controller daemon granting the request for bandwidth reservation.

2. The method of claim 1 , wherein the qualified bandwidth is determined by:

setting the qualified bandwidth to an initial value;

applying a test workload equal to the initial value to the file storage;

monitoring delivered I/O performance; and

refining the qualified bandwidth in response to the delivered I/O performance.

3. The method of claim 2 wherein the initial value is determined to be a fraction of fixed storage component bandwidth parameters.

4. The method of claim 1 wherein the qualified bandwidth is determined by iteratively:

applying a test workload equal to the qualified bandwidth and determining whether quality of service requirements are met by a present value of the qualified bandwidth; and

provided quality of service requirements are met, increasing the qualified bandwidth.

5. The method of claim 1 , further comprising monitoring at least one I/O metric of an I/O stream utilizing a granted bandwidth reservation, the at least one I/O metric being chosen from:

minimum observed bandwidth in a sample interval;

maximum observed bandwidth in a sample interval;

most recent observed bandwidth in the sample interval;

minimum observed I/O service time in the sample interval;

maximum observed I/O service time in the sample interval; and

most recent observed I/O service time in the sample interval.

6. The method of claim 5 wherein the sample interval is defined by a number of I/Os, up to a user configurable maximum.

7. The method of claim 5 wherein the sample interval is defined as a time, up to a user configurable maximum.

8. The method of claim 1 wherein the request for the bandwidth reservation comprises specifications of a required quality of service of the reservation, the method further comprising:

the controller daemon determining whether the specifications of the required quality of service can be met; and

provided the specifications of the required quality of service can be met, granting the request for bandwidth reservation.

9. A computer program product for use on a computer system for implementing a controller daemon for controlling utilization of file storage by a plurality of processes, the computer program product comprising a tangible computer usable medium having computer readable program code thereon, the computer readable program code comprising:

code for recording an empirically determined qualified bandwidth of the file storage;

code for maintaining a record of existing bandwidth reservations;

code for receiving at the controller daemon a request for a bandwidth reservation for access to the file storage by a process;

code for determining whether granting the request would result in a sum of bandwidth reservations which exceeds the qualified bandwidth; and

code for granting the request for bandwidth reservation, provided the qualified bandwidth would not be exceeded by granting the request.

10. A shared file system comprising:

a storage area network having a file volume; and

a plurality of nodes sharing access to the file volume;

wherein one of said nodes is configured as a controller node which stores an empirically determined qualified bandwidth of the file volume and maintains a record of existing bandwidth reservations;

wherein each of the plurality of nodes is configured to make a request to the controller node for a bandwidth reservation for access to the file volume;

wherein the controller node is configured to determine whether granting a node request for bandwidth reservation would result in a sum of bandwidth reservations which exceeds the qualified bandwidth; and

wherein the controller node is configured to grant the node request for bandwidth reservation, provided the qualified bandwidth would not be exceeded by granting the node request.

11. A method for controlling utilisation of shared file storage by a plurality of nodes, comprising:

establishing a controller daemon on a first node;

empirically determining a qualified bandwidth of the shared file storage;

the controller daemon maintaining a record of existing bandwidth reservations;

receiving at the controller daemon a request for a bandwidth reservation for access to the file storage by a process of one of the nodes;

the controller daemon determining whether granting the request would result in a sum of bandwidth reservations which exceeds the qualified bandwidth;

provided the qualified bandwidth would not be exceeded by granting the request, the controller daemon granting the request for bandwidth reservation; and

in the event of failure of the controller daemon, establishing the controller daemon on a second node.

Assignments (17)