Browse Prior Art Database

Power management for streaming data storage

IP.com Disclosure Number: IPCOM000015463D
Original Publication Date: 2002-Jan-26
Included in the Prior Art Database: 2003-Jun-20
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Abstract

Disclosed is a system for the storage subsystem which turns a part of storage subsystem into the low power mode by storing the data across the storage subsystem elements. The disclosed storage subsystem consists of the file system and two or more storage devices. The storage devices are grouped into two; group X is always running at the operational mode, and the other group Y is in the low power mode when there is not any ongoing access. The storage group Y switches from the low power mode to the operational mode on demand. The file system manages the allocation of storage space and maintains the data objects and the data attributes. The file system assigns the data objects to two storage device groups based on the data attribute. To maximize the amount of time that the storage group Y is in the low power mode and to minimize the latency of data retrieval caused by the transition from the low power mode to the operational mode, the disclosed storage subsystem applies the following rule for the storage space assignment. The streaming data is defined as an object accessed sequentially from beginning to the end at the constant (or near-constant) speed. The motion picture data and sound data are the example but not limited.

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Power management for streaming data storage

Disclosed is a system for the storage subsystem which turns a part of storage subsystem into the low power mode by storing the data across the storage subsystem elements.

The disclosed storage subsystem consists of the file system and two or more storage devices. The storage devices are grouped into two; group X is always running at the operational mode, and the other group Y is in the low power mode when there is not any ongoing access. The storage group Y switches from the low power mode to the operational mode on demand. The file system manages the allocation of storage space and maintains the data objects and the data attributes. The file system assigns the data objects to two storage device groups based on the data attribute.

To maximize the amount of time that the storage group Y is in the low power mode and to minimize the latency of data retrieval caused by the transition from the low power mode to the operational mode, the disclosed storage subsystem applies the following rule for the storage space assignment.

- The streaming data is defined as an object accessed sequentially from beginning to the end at the constant (or near-constant) speed. The motion picture data and sound data are the example but not limited.

- The file system splits a streaming data object into two sections based on the speed S (bytes/sec) and the time T (sec) factors; where S is the speed at that the streaming data is played back, and T i...