Abstract: Methods and apparatus facilitate the management of input/output (I/O) subsystems in virtual I/O servers to provide appropriate quality of services (QoS). A hierarchical QoS scheme based on partitioning of network interfaces and I/O subsystems transaction types are used to classify Virtual I/O communications. This multi-tier QoS method allows virtual I/O servers to be scalable and provide appropriate QoS granularity.

Abstract: An example embodiment of the present invention provides processes relating to direct memory access (DMA) for nodes in a distributed shared memory system with virtual storage. The processes in the embodiment relate to DMA read, write, and push operations. In the processes, an initiator node in the system sends a message to the home node where the data for the operation will reside or presently resides, so that the home node can directly receive data from or send data to the target server, which might be a virtual I/O server. The processes employ a distributed shared memory logic circuit that is a component of each node and a connection/communication protocol for sending and receiving packets over a scalable interconnect such as InfiniBand. In the example embodiment, the processes also employ a DMA control block which points to a scatter/gather list and which control block resides in shared memory.

Abstract: An example embodiment of the present invention provides processes relating to a connection/communication protocol and a memory-addressing scheme for a distributed shared memory system. In the example embodiment, a logical node identifier comprises bits in the physical memory addresses used by the distributed shared memory system. Processes in the embodiment include logical node identifiers in packets which conform to the protocol and which are stored in a connection control block in local memory. By matching the logical node identifiers in a packet against the logical node identifiers in the connection control block, the processes ensure reliable delivery of packet data. Further, in the example embodiment, the. logical node identifiers are used to create a virtual server consisting of multiple nodes in. the distributed shared memory system.

Abstract: An example embodiment of the present invention provides processes relating to a connection/communication protocol and a memory-addressing scheme for a distributed shared memory system. In the example embodiment, a logical node identifier comprises bits in the physical memory addresses used by the distributed shared memory system. Processes in the embodiment include logical node identifiers in packets which conform to the protocol and which are stored in a connection control block in local memory. By matching the logical node identifiers in a packet against the logical node identifiers in the connection control block, the processes ensure reliable delivery of packet data. Further, in the example embodiment, the logical node identifiers are used to create a virtual server consisting of multiple nodes in the distributed shared memory system.