International Business Machines Corporation

University of California

Darrell D Long

Randal Chilton Burns

Benjamin Clay Reed

Edward Gustav Chron

Luis Felipe Cabrera

Thomas M Kroeger

A data management system for storage area networks (SANs) includes an authentication and directory service that integrates the management of cache coherency and synchronization into an authentication mechanism, referred to herein as a ticket. The data in the system is notionally classified into colors. When a principal computer requests a read or a write access to data of a particular &ldquo;color&rdquo;, the service determines whether the principal is authorized for the requested access, and if so, the service issues a ticket to the principal that specifies a data color that the bearer of the ticket is authorized to access using the type of access mechanism specified on the ticket. A hidden &ldquo;hue&rdquo; can also be specified on the ticket. The service can variously inform principals to cancel tickets based on color or time of issue and can also variously inform storage devices not to honor tickets of a certain hue or time of issue as appropriate to thereby maintain cache coherency and data consistency.

System and method for managing authentication and coherency in a storage area network

A decentralized file system based on a network of remotely encrypted storage devices is disclosed. The file system includes a network to which a network client, a secure remotely encrypted storage device, a key manager, and a lock manager are attached. The system organizes data as files and directories. Files or directories are composed of one or more streams, which logically partition the data associated with the files or directories. The device serves as a repository of the system's data. The key manager controls data access keys while the lock manager handles consistency of the files. A network user may have read or write access to a file. Access is controlled using keys and access lists maintained by the key manager.

Decentralized remotely encrypted file system

The present invention discloses a method, apparatus, and article of manufacture for generating, transmitting, replicating, and rebuilding in-place reconstructible software updates to a file from a source computer to a target computer updates to a file from a source computer to a target computer. The present invention stores the first version of the file and the updates to the first version of the file in the memory of the source computer. The first version is also stored in the memory of the target computer. The updates are then transmitted from the memory of the source computer to the memory of the target computer. The present invention uses these updates at the target computer to build the second version of the file in-place.

Method for generating and reconstructing in-place delta files

A network storage device is disclosed for use in a secure array of such devices to support a distributed file system. Each device is an independent repository of remotely encrypted data objects to be accessed by authorized network clients. All encryption is done by the clients, rather than by the devices. In order for the system to revoke access to an object on the device, the object must be re-encrypted. Each storage device has a device owner for controlling access to the device's data. All data requests from the clients and responses to them are authenticated using keys derived from the owner key and hashed message authentication codes.

Secure array of remotely encrypted storage devices

A method and apparatus that maintains in stable storage an identification of which copies in a mirrored disk system are currently up to date without requiring the use of a logging mechanism. The invention may include a plurality of mirrored disk drives and a processing unit for controlling the writing and reading of data units to and from mirrored disk drives, wherein the processing unit establishes and maintains cohort sets for each mirrored disk drive. The cohort set represents the status of copies of the data units stored on the mirrored disk drives and contains membership information for redundant copies of data units stored in the plurality of mirrored disk drives. The membership information comprises a data structure of 2n status bits for identifying which disks contain current copies of the data units, where n is the number of disks in the system, and wherein the first n bits are used to indicate an intention to update the membership information for the copies and the second n bits are used indicate a current state of the membership information. The data structure may further include log(n) additional bits for identifying each mirrored disk.

Method and apparatus for establishing and maintaining the status of

A method of tracking events and their sequences in a computer system and predicting the probability of future events using a data structure that represents the predictive nature of the system after an initial event correlating to an object in the system. The invention reduces memory requirements and computational complexity by partitioning a trie into subtries where each subtrie represents a set of sequences of events, statically limiting the size of the partitions by limiting the number of descendants below the node defining the partition, and refreshing parts of the set of children and releasing slots occupied by particular descendants when additional space is needed. In addition, each partition can be attached to the object which it represents and moved in and out of memory with that object. In this way, data structures which would otherwise grow as large as N.sup.O and which have a computational complexity of predictions on the order of O.times.N, where N is the number of objects modeled and O is the model order, will be limited in size to N which, in turn, limits the computational complexity to order O.

Growing community of inventors

Soquel, CA, United States of America

Darrell D Long