Method and apparatus for distributed topology function in serial attached small computer system interface (SAS)

摘要

The present invention is directed at a method and apparatus for determining a distributed Serial Attached Small computer system interface (SAS) topology in a storage network system. Once a SAS storage network element, such as a SAS Expander, receives notification that a downstream SAS topology has changed, the SAS Expander queries all downstream SAS Expanders to update its route table.

主权项

1. In a Serial Attached Small Computer System Interface (SAS) domain including a set of SAS storage network elements, a method of configuring an Expander route table of a SAS Expander in a distributed manner comprising:
receiving notification of a trigger event by an initiator at SAS Expander closest to the initiator; determining a set of paths originating from said SAS Expander based on an origin of topology change; determining a list of Expanders to query based on said set of paths; said list of Expanders to query including a first encountered self-configuring or last-in-path Expander and intermediate non self-configuring SAS Expanders for each path; wherein determining comprises calling a self-configuring process; determining a set of route table information from a set of SAS Expanders in said list of Expanders to query; updating route tables of the intermediate non self-configuring (NSCFG) SAS Expanders in a distributed manner; wherein said updating comprises calling a non-self-configuring process; and configuring said Expander route table based on said set of route table information; wherein the determining, updating and configuring are performed in an iterative sequence originating from the initiator.