Patent ID: 7506094

Claim:
In a distributed computing system provided with multiple root nodes, and further provided with one or more PCI switches and one or more PCI adapters that are available for accessing by different root nodes, a computer program product in a computer readable medium comprising: first instructions for initially designating one of said root nodes to be master root node; second instructions for operating said master root node to configure routings through said PCI switches, each of said configured routings corresponding to only a single one of said root nodes, and each routing providing a path for data traffic between its corresponding root node and one of said PCI components; and third instructions for enabling any particular root node to access only PCI switches and adapters which are included in configured routings that correspond to said particular root node, wherein each root node includes a host CPU set, and a root complex comprising structure for connecting the root node to at least one of said PCI switches, so that each of said routings provides a path for data traffic between the root complex of its corresponding root node, and one of said PCI adapters; only said master root node is enabled to issue write operations, and the master root node furnishes configured routing information to each of the remaining root nodes through its root complex, and thus enables the root complex of a remaining root node to access PCI switches and adapters indicated by its received routing information; and a plurality of options are made available for selection in order to respectively modify host CPU sets of said remaining root nodes, one of said options comprising modifying said host CPU set of said remaining root nodes to direct them to use the master root node as a proxy for write operations and another of said options comprising modifying said host CPU sets of said remaining root nodes to prevent them from issuing write operations.