Storage Technology Corporation

Perry Wayde Merritt

Charles Allen Milligan

Kenneth L Willis

Stephen S Selkirk

Edward T Gladstone

James Boyd Lenehan

Paul David VonBehren

Linda Joyce Selkirk, Legal Represenative

Ian Fraiser Reeve

June Mullins

Edward D Gladstone

A system is provided to support dynamically changeable virtual mapping schemes in a data processing system. The present invention separates processing of data unit requirements from the selection of which storage subsystems to use for storage by using a storage methodologies inventory. A stored data management subsystem contains one or more hosts. A plurality of data storage elements is functionally coupled to the one or more hosts. The plurality of data storage elements is organized using a plurality of layers of mapping tables. The plurality of layers of mapping tables provides unique identification of location of the data such that individual data entries in a mapping table is variable and self-defining with respect to the amount of data managed.

Dynamically changeable virtual mapping scheme

A mechanism is provided for storing self-defining data and mapping elements with either a fixed set of allowed structures or types or with the structures and types determined by rules. Recovery is enhanced by the use of backward and forward pointers between data and mapping elements for the data elements in the order written by the management algorithm. Recovery is also enhanced by the use of companion pointers with metadata. The companion pointers may include pointers to data or mapping elements that are part of the same structural grouping. The metadata may describe the structural grouping. The metadata may also include pointers to the previous and/or next versions of the same elements. Recovery of the data and/or mapping structures is achieved by the reverse application of the management algorithm.

Rebuilding of dynamic maps and data managed thereby

A virtual stored data management system is provided. In one embodiment, the management system includes one or more hosts and a plurality of data storage elements functionally coupled to the hosts. Each data storage element includes a host network attachment, data transfer means, a storage controller, and permanent data storage media. The permanent data storage media is organized with management information uniquely associated with units of the data such that the management information may be manipulated in several different locations within the management system substantially simultaneously. Thus, the organization of the management processes allows for the management information to be processed, used, changed, or modified in several different locations within the management system at any particular instance. Provision is made for the internal processes to discover the current location of the processing, for the location to be changed as directed, and for the processing to be kept consistent when done in more than one place simultaneously.

Floating virtualization layers

Recovery of dynamic maps and data managed thereby

The intelligent data storage manager functions to optimize the data storage utilization in a RAID data storage subsystem that is equipped with a heterogeneous mix of data storage elements. This is accomplished by using preference groups and biasing the writing of stripes of data in the redundancy groups of the RAID system to the disk drive or a set of disk drives in the preference group that have the greatest available data storage capacity. This ensures that the data storage capacity of the the disk drive with the largest available capacity is utilized to the maximum capacity. A preference group comprises a group of disk drives that is larger than the stripe size that is used to store data in a RAID format. The data storage manager does not write data across all of the disk drives in the preference group at a time, but rotates the collection of disk drives that are used to write a stripe of data. Therefore, if there is a failure of one of the disks in the RAID preference group, only a portion of the stripes stored therein need to be reconstructed, thereby speeding the reconstruction process. By including the the disk drive(s) with the largest available capacity in every stripe that is written to the preference group, the data storage capacity of the disk drive with the largest available capacity is preferentially used in the storage of data, thereby using this excess capacity first, with the utilization of the data storage capacity of this disk drive being related to the ratio of the preference group size to the RAID stripe size.

System for optimizing data storage in a RAID system

Growing community of inventors

Broomfield, CO, United States of America

Perry Wayde Merritt