| US 7,574,630 B1 | ||
| Method and system for reliable access of expander state information in highly available storage devices | ||
| Samantha L. Ranaweera, Cranberry Township, Pa. (US); and Andrew Reynolds, Mars, Pa. (US) | ||
| Assigned to Network Appliance, Inc., Sunnyvale, Calif. (US) | ||
| Filed on Aug. 14, 2006, as Appl. No. 11/504,200. | ||
| Int. Cl. G06F 11/00 (2006.01) | ||
| U.S. Cl. 714—43 | 32 Claims |
| 1. A method, in a storage system which has first and second expanders that are configured to couple to a plurality of devices,
the method comprising:
detecting an interface failure of a first interface of the first expander, wherein the first interface is configured to retrieve
state information of the storage system for the first expander; and
retrieving the state information from a second expander to the first expander using a second interface of the first expander
when the interface failure of the first interface is detected, wherein the state information normally available to the first
expander through the first interface is unavailable through the first interface due to the interface failure of the first
interface, wherein retrieving the state information from the second expander comprises:
notifying the second expander of the interface failure by sending an interrupt from a first driver of a first operating system,
associated with the first expander, to a second driver of a second operating system, associated with the second expander;
and
receiving the state information from the second expander in response to notifying the second expander of the interface failure.
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