System and method for performing virtual device I/O operations
View Patent ↗Systems, methods, apparatus and software can make use of separated I/O processors and strategy processors (implemented in hardware and/or software) to perform virtual device I/O operations. I/O processors operating on cluster nodes, storage appliance ports, or other devices can receive I/O operation requests directed to virtual devices, e.g., volumes or virtual logical units. Information about the request is forwarded to a strategy processor, operating independently or as part of larger volume management software where corresponding physical device I/O operations are determined. The physical device I/O operations can include additional information about the operations, e.g., tag information and summary information, for use in processing the virtual device I/O request. The physical device I/O operations are sent back to the I/O processor which executes the operations and/or passes the operation on to the appropriate storage device. I/O completion messages are sent by the I/O processor in parallel to the source of the I/O request (e.g., a host or application) and to the strategy processor, providing an improvement in I/O latency.
1. A method implemented in a computer system, comprising:
causing a processor of said computer system to extract information from a virtual device input/output (I/O) operation request;
causing said processor to form a message, wherein
said message is formed using said information,
said message is formed such that said message is configured to allow at least one physical device I/O operation to be formed from at least a portion of said message, and
said message and said virtual device I/O operation request are distinct from one another; and
causing said processor to effect transmission of said message.
2. The method of claim 1 , wherein
said transmission of said message transmits said message to a strategy processor.
3. The method of claim 2 , wherein
said virtual device I/O operation request is directed to at least one of
a volume, and
a logical unit.
4. The method of claim 2 , further comprising:
receiving said virtual device I/O operation request;
receiving data corresponding to said virtual device I/O operation request; and
performing a computation using said data.
5. The method of claim 2 , wherein
said information from said virtual device I/O operation request comprises a virtual device destination.
6. The method of claim 2 , wherein
said message comprises an indication of a remote I/O operation request.
7. The method of claim 2 , further comprising:
receiving said message at said strategy processor; and
forming said at least one physical device I/O operation, wherein said forming uses said information.
8. The method of claim 7 , wherein said forming said at least one physical device I/O operation further comprises:
using information about organization of at least one virtual device.
9. The method of claim 7 , further comprising:
transmitting said at least one physical device I/O operation to an I/O processor; and
executing said at least one physical device I/O operation against at least one storage device.
10. The method of claim 2 , further comprising:
receiving said at least one physical device I/O operation formed using said information; and
executing said at least one physical device I/O operation against at least one storage device.
11. The method of claim 2 , further comprising:
receiving said message at said strategy processor; and
forming said at least one physical device I/O operation, wherein
said forming said at least one physical device I/O operation uses said information, and
said message comprises said information.
12. The method of claim 11 , wherein said forming said at least one physical device I/O operation further comprises at least one of
generating additional data,
repairing stored data, and
refreshing said stored data.
13. The method of claim 11 , further comprising:
transmitting said at least one physical device I/O operation to an I/O processor for execution against at least one storage device.
14. The method of claim 13 , further comprising:
determining whether said virtual I/O operation request is associated with a node that received said virtual I/O operation request.
15. The method of claim 13 , wherein
said at least one physical device I/O operation further comprises at least one physical device command and data associated with said at least one physical device command.
16. The method of claim 13 , further comprising:
receiving said at least one physical device I/O operation at said I/O processor; and
executing said at least one physical device I/O operation against said at least one storage device, wherein
said at least one storage device is coupled to said I/O processor.
17. The method of claim 16 , further comprising:
receiving an indication from said I/O processor that said at least one physical device I/O operation has been successfully executed.
18. A computer system comprising:
a processor;
a computer readable medium coupled to said processor; and
computer code, encoded in said computer readable medium, configured to cause said processor to
extract information from a virtual device input/output (I/O) operation request,
form a message, wherein
said message is formed using said information,
said message is formed such that said message is configured to allow at least one physical device I/O operation to be formed from at least a portion of said message, and
said message and said virtual device I/O operation request are distinct from one another, and
transmit said message.
19. A computer program product, comprising a computer readable medium storing a plurality of instructions, wherein said instructions, when executed by a processor of a computer system, are configured to cause said processor to:
extract information from a virtual device input/output (I/O) operation request;
form a message, wherein
said message is formed using said information,
said message is formed such that said message is configured to allow at least one physical device I/O operation to be formed from at least a portion of said message, and
said message and said virtual device I/O operation request are distinct from one another; and
transmit said message.