Patent Number: 7,089,435

Title: Storage unit having normal and backup power sources for use in retaining data when normal power fails

Abstract: A feeding technique for a storage unit is provided, in which power can be supplied from an optimum power source depending on an operation mode of a cache memory, the stable switching of feeding paths can be performed, and the feeding with high voltage accuracy and small voltage variation can be achieved. For its achievement, the feeding system in the RAID system including a hard disk drive, a disk adaptor, a channel adaptor, and a cache memory is provided. The feeding system includes a DC-DC power source to supply, to the cache memory, the voltage for a normal operation mode in which the data is written/read to/from the cache memory, and a DC-DC power source to supply, to the cache memory, the voltage for a backup operation mode in which the data stored in the cache memory is retained, and the power sources are switched during the feeding depending on the operation mode of the cache memory.

Inventors: Kawakubo; Yosuke (Odawara, JP)

Assignee: Hitachi, Ltd.

International Classification: G06F 1/26 (20060101)

Expiration Date: 8/08/02018