Patent ID: 7949902

Claim:
A failure analysis system, comprising: a controller A that sends a control command A; a looped interface A, said controller A being selectively connectable to said looped interface A; a looped interface B; a plurality of node devices A that are selectively connectable to said looped interface A, said node devices A comprising a disk device; a plurality of node devices B that are selectively connectable to said looped interface A, said node devices B comprising a disk device; a controller B that sends a control command B, said controller B being selectively connectable to said looped interface B; and an enclosure service device A that receives said control command A via said node devices A and an Enclosure Service Interface (ESI), wherein said node devices A and B are mutually exclusively connected to said controllers A and B, respectively, and wherein: if a failure occurs in both the looped interfaces A and B, said enclosure service device A: selectively disconnects less than all of said node devices B from said looped interface A; and one of: maintains said node devices A connected to said looped interface A; and disconnects and subsequently re-connects said node devices A to said looped interface A.