Coalescing change notifications in an I/O virtualization system
View Patent ↗Efficient and effective mechanisms for coalescing change notifications such as Registered State Change Notifications (RSCNs) are provided. Multiple hosts are connected to an I/O director that allows virtualization of I/O resources including Host Bus Adapters (HBAs) for the various hosts. The I/O director is connected to a Fiber Channel switch. When an RSCN is received by the I/O director, the I/O director queries to Fiber Channel fabric to identify the state change and maintains information about the RSCN so that subsequent redundant RSCNs can be discarded. Change notification information is forwarded to the appropriate hosts connected to the I/O director.
1. A method, comprising:
receiving a first change notification from a Fibre Channel (FC) fabric indicating a changed state of an origin of the change notification;
identifying the origin of the first change notification;
mapping the origin of the first change notification to a plurality of virtual Host Bus Adapters (VHBAs);
maintaining identification information for the first change notification;
forwarding change notification information to a plurality of servers corresponding to the plurality of VHBAs;
receiving a second change notification from the FC fabric, the second change notification received subsequent to the first change notification;
determining whether the second change notification has identification information matching the identification information maintained for the first change notification; and
in response to determining the second change notification has identification information matching the identification information maintained for the first change notification, discarding the second change notifications, wherein the change notifications are Registered State Change Notifications (RSCN) and wherein forwarding change notification information comprises forwarding the RSCN.
2. The method of claim 1 , further comprising querying the FC fabric for information about a change in state corresponding to the first change notification.
3. The method of claim 1 , wherein the origin of the first change notification is a node in the FC fabric.
4. The method of claim 1 , wherein mapping the origin of the first change notification to the plurality of vHBAs comprises accessing a mapping table associating storage to corresponding vHBAs.
5. The method of claim 1 , wherein the first change notification is received at an I/O director.
6. The method of claim 5 , wherein the I/O director is configured to provide virtualized I/O resources to a plurality of individual servers.
7. The method of claim 5 , wherein the I/O director is connected to an FC switch using physical Host Bus Adapters (HBAs) and is connected to a plurality of servers over an Infiniband network.
8. The method of claim 1 , wherein the first change notification is received at a vHBA interface comprising a plurality of vHBAs.
9. A system, comprising:
a processor; and
a memory coupled with the processor and storing a set of instructions which, when executed by the processor, causes the processor to coalesce change notifications by:
receiving a first change notification from a Fibre Channel (FC) fabric indicating a changed state of an origin of the change notification;
identifying the origin of the first change notification;
mapping the origin of the first change notification to a plurality of virtual Host Bus Adapters (VHBAs);
maintaining identification information for the first change notification;
forwarding change notification information to a plurality of servers corresponding to the plurality of VHBAs;
receiving a second change notification from the FC fabric, the second change notification received subsequent to the first change notification;
determining whether the second change notification has identification information matching the identification information maintained for the first change notification; and
in response to determining the second change notification has identification information matching the identification information maintained for the first change notification, discarding the second change notifications, wherein the change notifications are Registered State Change Notifications (RSCN) and wherein forwarding change notification information comprises forwarding the RSCN.
10. The system of claim 9 , further comprising querying the FC fabric for information about a change in state corresponding to the first change notification.
11. The system of claim 9 , wherein the origin of the first change notification is a node in the FC fabric.
12. The system of claim 9 , wherein mapping the origin of the first change notification to the plurality of vHBAs comprises accessing a mapping table associating storage to corresponding vHBAs.
13. The system of claim 9 , wherein the first change notification is received at an I/O director.
14. The system of claim 13 , wherein the I/O director is configured to provide virtualized I/O resources to a plurality of individual servers.
15. The system of claim 13 , wherein the I/O director is connected to an FC switch using physical Host Bus Adapters (HBAs) and is connected to a plurality of servers over an Infiniband network.
16. A computer-readable memory storing a set of instructions which, when executed by a processor, cause the processor to coalesce change notifications by:
receiving a first change notification from a Fibre Channel (FC) fabric indicating a changed state of an origin of the change notification;
identifying the origin of the first change notification;
mapping the origin of the first change notification to a plurality of virtual Host Bus Adapters (VHBAs);
maintaining identification information for the first change notification;
forwarding change notification information to a plurality of servers corresponding to the plurality of VHBAs;
receiving a second change notification from the FC fabric, the second change notification received subsequent to the first change notification;
determining whether the second change notification has identification information matching the identification information maintained for the first change notification; and
in response to determining the second change notification has identification information matching the identification information maintained for the first change notification, discarding the second change notifications, wherein the change notifications are Registered State Change Notifications (RSCN) and wherein forwarding change notification information comprises forwarding the RSCN.