Patent ID: 6738870
Filing Date: 2004-05-18
Classification: G06F

Abstract:
A high speed remote storage controller system for a computer system having cluster nodes of symmetric multiprocessors, comprisingone or more remote storage controllers each having an associated local interface controller, and a local-to-remote data bus, and the one or more remote storage controllers responsive to a remote management system for managing the resources comprising the remote storage controller for data accesses between clusters of symmetric multiprocessors which are controlled for inter nodal storage operations by one of said remote storage controller system, each of which clusters has a plurality of processors, a shared cache memory, a plurality of I/O adapters and a main memory accessible from the cluster, said remote store controller while processing data accesses across a plurality of clusters for data storage operations involving shared memory and inter nodal storage operations, enlisting a single one of said remote storage controller to perform remote cast outs, store requests from an I/O adapter, main storage padding operations, and main memory move page operations and while performing remote data storage operations to main memory, said enlisted single remote storage controller also handles cross cluster invalidations associated with maintaining inter-nodal cache coherency for said computer system having cluster nodes of symmetric multiprocessors, and which contains a deadlock avoidance mechanism designed to detect inter-nodal deadlocks which normally result from one resource on a local cluster waiting for a second resource on a remote cluster which is deadlocked against a third resource on said remote cluster waiting for a fourth resource on the local cluster which is deadlocked against said first resource on the local cluster, and which employs a fast hang quiesce mechanism embedded in each remote storage resource which works in conjunction with similar fast hang quiesce mechanisms throughout the System Controller to prevent system-wide hangs either caused by the failure of the current remote storage resource to make forward progress or by the failure of another operation somewhere in the Storage Controller to make forward progress.