System and method for dynamically loadable storage device I/O policy modules
Systems, methods, apparatus and software can implement a multipathing driver using dynamically loadable device policy modules that provide device specific functionality for providing at least one of input/output (I/O) operation scheduling, path selection, and I/O operation error analysis. Because the device policy modules include device specific functionality, various different devices from different manufacturers can be more efficiently and robustly supported.
1. An apparatus comprising:
means for storage device discovery configured to gather information regarding at least one storage device, wherein
a distributed computing system is comprised of the at least one storage device;
means for directing input/output (I/O) operations along at least one of a plurality of communication pathways to the at least one storage device;
means for providing storage-device-specific I/O operation scheduling and communication pathway selection in conjunction with the means for directing I/O operations;
means for selectively making the means for providing storage-device-specific I/O operation scheduling and communication pathway selection available to the means for directing I/O operations; and
multipath driver in communication with the means for storage device discovery and configured to direct input/output (I/O) operations along at least one of the communication pathways to the at least one storage device.
2. The apparatus of claim 1 further comprising:
means for discovering the presence of at least one storage device belonging to a distributed computing system; and
means for communicating information about the at least one storage device to the means for directing I/O operations.
3. The apparatus of claim 1 further comprising:
means for registering the means for providing storage-device-specific I/O operation scheduling and communication pathway selection with the means for directing I/O operations.
4. The apparatus of claim 1 wherein the means for directing I/O operations further comprises means for providing a fixed set of I/O policies including at least one of a function, a procedure, and an object-oriented method operable to perform at least one of I/O operation scheduling, path selection, and I/O operation error analysis.
5. The apparatus of claim 1 , further comprising:
means for loading the means for directing I/O operations along the at least one of the plurality of communication pathways to the at least one storage device.
6. A method comprising:
gathering information regarding at least one storage device, wherein
the gathering is performed by a storage device discovery module, and
a distributed computing system comprises the at least one storage device;
directing input/output (I/O) operations along at least one of a plurality of communication pathways to the at least one storage device, wherein
the directing is performed by a multipath driver, and
the storage device discovery module and multipath driver are coupled to one another;
providing storage-device-specific I/O operation scheduling and communication pathway selection in conjunction with the directing the I/O operations, wherein
the providing is performed by a device policy module; and
selectively making the device policy module available to the multipath driver.
7. The method of claim 6 further comprising:
discovering the presence of at least one storage device belonging to a distributed computing system; and
communicating information about the at least one storage device to the multipath driver.
8. The method of claim 6 further comprising:
registering the device policy module with the multipath driver.
9. The method of claim 6 , wherein the directing I/O operations further comprises:
providing a fixed set of I/O policies including at least one of a function, a procedure, and an object-oriented method operable to perform at least one of I/O operation scheduling, path selection, and I/O operation error analysis.
10. The method of claim 6 , further comprising:
loading the multipath driver along the at least one of the plurality of communication pathways to the at least one storage device.
11. The computer system comprising:
at least one processor;
a computer-readable storage medium coupled to the at least one processor; and
computer-code, encoded in the computer-readable storage medium, configured to cause the at least one processor to
gather information regarding at least one storage device, wherein the gathering is performed by a storage device discovery module, and
a distributed computing system comprises the at least one storage device,
direct input/output (I/O) operations along at least one of a plurality of communication pathways to the at least one storage device, wherein
the directing is performed by a multipath driver, and
the storage device discovery module and multipath driver are coupled to one another,
provide storage-device-specific I/O operation scheduling and communication pathway selection in conjunction with the directing I/O operations, wherein
the providing is performed by a device policy module, and
selectively make the device policy module available to the multipath driver.
12. The computer system of claim 11 , wherein the computer code is further configured to cause the processor to:
discover the presence of at least one storage device belonging to a distributed computing system; and
communicate information about the at least one storage device to the multipath driver.
13. The computer system of claim 11 , wherein the computer code is further configured to cause the processor to:
register the device policy module with the multipath driver.
14. The computer system of claim 11 , wherein the computer code configured to direct I/O operations is further configured to cause the processor to
provide a fixed set of I/O policies including at least one of a function, a procedure, and an object-oriented method operable to perform at least one of I/O operation scheduling, path selection, and I/O operation error analysis.
15. The computer system of claim 11 , wherein the computer code is further configured to cause the processor to:
load the multipath driver along the at least one of the plurality of communication pathways to the at least one storage device.
16. A computer-readable storage medium comprising computer code, when executed, the computer code is configured to cause a processor to
gather information regarding at least one storage device, wherein
the gathering is performed by a storage device discovery module, and
a distributed computing system comprises the at least one storage device;
direct input/output (I/O) operations along at least one of a plurality of communication pathways to the at least one storage device, wherein
the directing is performed by a multipath driver, and
the storage device discovery module and multipath driver are coupled to one another;
provide storage-device-specific I/O operation scheduling and communication pathway selection in conjunction with the directing the I/O operations, wherein
the providing is performed by a device policy module; and
selectively make the device policy module available to the multipath driver.
17. The computer-readable storage medium of claim 16 , wherein the computer code, when executed, is further configured to cause the processor to
discover the presence of at least one storage device belonging to a distributed computing system; and
communicate information about the at least one storage device to the multipath driver.
18. The computer-readable storage medium of claim 16 , wherein the computer code, when executed, is further configured to cause the processor to
register the device policy module with the multipath driver.
19. The computer-readable storage medium of claim 16 , wherein the computer code configured to direct I/O operations, when executed, is further configured to cause the processor to:
provide a fixed set of I/O policies including at least one of a function, a procedure, and an object-oriented method operable to perform at least one of I/O operation scheduling, path selection, and I/O operation error analysis.
20. The computer-readable storage medium of claim 16 , wherein the computer code, when executed, is further configured to cause the processor to:
load the multipath driver along the at least one of the plurality of communication pathways to the at least one storage device.