Patent ID: 8499184
Filing Date: 2013-07-30
Classification: G06F,Y02D

Abstract:
1. A method of operating a storage system following a power loss, comprising: detecting a loss of power from a primary power supply; preventing receipt of input/output commands at a cache memory in response to detecting the loss of power; copying contents in the cache memory to a non-volatile memory in response to detecting the loss of power; detecting resumption of the primary power supply; charging a secondary power supply utilizing the primary power supply; copying contents of the non-volatile memory back to the cache memory in response to detecting the resumption of the primary power supply; transmitting the contents of the cache memory to at least one storage volume while continuing prevention of receipt of input/output commands at the cache memory; detecting that a charge stored on the secondary power supply exceeds a first threshold amount of charge required to copy the contents of the cache memory to the non-volatile memory by a predetermined amount; enabling receipt of the input/output commands at a reduced rate in response to detecting that the charge stored on the secondary power supply exceeds the first threshold amount of charge, wherein: detecting that the charge stored on the secondary power supply has reached a second threshold amount; and allowing receipt of the input/output commands at a full rate at the of the cache memory in response to detecting that the charge stored on the secondary power supply has reached the second threshold amount.