Inventors:
Lewis L. Nunnelley - San Jose CA
Larry L. Williams - Los Altos CA
Leighton C. Wood - Morgan Hill CA
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G06F 126
Abstract:
A data storage and retrieval system is provided which has extremely high capacity. The system includes a large array of small disk files, and three storage managers for controlling the allocation of data to the array, access to data, and the power status of disk files within the array. The allocation manager chooses the disk files upon which incoming data is written based on the current state of the disk files (active or inactive), the available capacity, and the type of protection desired (i. e unprotected, RAID), mirrored, etc. ). The access manager interprets incoming read requests to determine the location of the stored data. The power manager sequences disk files between active and inactive to provide the storage requested by the access and allocation managers. The power manager also maintains the disk array in conformance with thermal and power constraints to avoid excessive power consumption or thermal overload while keeping active the optimal subset of the disk array based on the storage requests pending at any point in time.