Method and apparatus for detecting and preemptively ameliorating potential logic unit thrashing in a storage system having multiple requestors

A computer program product residing on a computer usable medium for detecting and preemptively ameliorating potential logic unit thrashing in a storage system having an active-passive pair of controllers, said computer program product comprising:

• program code means for selecting one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that each of at least two requesters has usable access to both of said active-passive pair of controllers;
• program code means for selecting said only one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that one of said at least two requesters has usable access to only one of said active-passive pair of controllers;
• and
• program code means for selecting one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that each of said at least two requesters has usable access only to different ones of said active-passive pair of controllers.

An apparatus for detecting and preemptively ameliorating potential logic unit thrashing in a storage system having an active-passive pair of controllers, said apparatus comprising:

• means for selecting one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that each of at least two requesters has usable access to both of said active-passive pair of controllers;
• means for selecting said only one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that one of said at least two requesters has usable access to only one of said active-passive pair of controllers;
• and
• means for selecting one of said active-passive pair of controllers to be designated as an active resource controller, in response to detecting that each of said at least two requesters has usable access only to different ones of said active-passive pair of controllers.