Hewlett-packard Development Company, L.p.

Other

Hewlett Packard Enterprise Development LP

Newport Corporation

Eric A Anderson

Xiaozhou Li

Joseph Andrew Tucek

John Johnson Wylie

Mehul A Shah

Christopher Edward Hoover

Arif Abdulhusein Merchant

Mustafa Uysal

Kimberly Keeton

Alistair Veitch

Vyacheslav M Ryaboy

Worthington Bowie Houghton, Jr

Tim Reddin

Robert J Souza

Charles E Christian, Jr

Jack Marcinkowski

Ludmila Cherkasova

Naveen Muralimanohar

John Wilkes

Jeffrey Clifford Mogul

Ram Swaminathan

Richard Andrew Golding

Guillermo Alvarez

Susan Spence

Geoffrey E Dolbear

Robert Roy Peters

Walter A Maier

Jain Nitin

Amitanand Aiyer

Allstair Veitch

Peter A Nick

Hugh Hunnicutt

Michael Hobbs

John T Ziegenhorn

Ted Romer

A method is provided for scrubbing information stored in a data storage system where the information is stored as a plurality of encoded fragments across multiple storage devices. The method includes maintaining on a first storage device a list of metadata entries corresponding to values that are stored in the data storage system at an At Maximum Redundancy (AMR) state, verifying that encoded fragments associated with each of the metadata entries are stored on a second storage, verifying that a corresponding metadata entry is stored on the first storage device for each encoded fragment that is stored on the second storage device, and scheduling for recovery any missing encoded fragments and/or any missing metadata entry.

Scrubbing procedure for a data storage system

Embodiments include methods, apparatus, and systems for retrieving data from multiple locations in storage systems. One embodiment includes a method that determines that data is stored in multiple locations remote to a computer, estimates a latency to retrieve the data from the multiple locations, and requests the data from the plural locations.

Retrieving data from multiple locations in storage systems

A method for dynamically partitioning a B-tree data structure, includes: determining if the B-tree data structure requires a partition; establishing a midpoint of the B-tree data structure; migrating from a beginning of the B-tree data structure to the midpoint of the B-tree data structure to a first B-tree data structure; migrating from the midpoint of the B-tree data structure to an end of the B-tree data structure to a second B-tree data structure; and allowing normal operations on the B-tree data structure during migration.

Dynamic partitioning of a data structure

A hard disk drive includes a storage surface, a motor, a read/write had, and a number of regions into which the storage surface is divisible. Data is writable to and data is readable from the storage surface. The motor is to rotate the storage surface at a variable speed. The read/write head is to write data to and read data from the storage surface while the storage surface is rotated by the motor. Each region corresponds to a different speed at which the storage surface is rotated for the read/write head to write data to and read data from the region.

Hard disk drive having regions corresponding to different speeds at which storage surface rotates

Example methods, apparatus, and articles of manufacture to access memory are disclosed. A disclosed example method involves receiving at least one runtime characteristic associated with accesses to contents of a memory page and dynamically adjusting a memory fetch width for accessing the memory page based on the at least one runtime characteristic.

Methods and apparatus to access memory using runtime characteristics

A method for determining priority of recovery for a RAID implementation includes detecting a first failure of the RAID implementation; detecting a second failure of the RAID implementation; assigning a first priority to the first failure and a second priority to the second failure; and setting the priority of the recovery based on the first priority and the second priority.

Prioritizing recovery in a storage system implementing raid

A method for inserting a file in a search tree (B-tree) implemented on a file system, includes: (a) in response to a current node being a root node or an internal node, determining a child node; (b) repeating (a) until a leaf node is detected; (c) in response to a number of leaf nodes at a level of the leaf node exceeding an upper limit of files or a number of child nodes of a current node exceeding an upper limit of sub-directories, balancing the level of the leaf node or child nodes; and (d) inserting the file at the level of the leaf node.

File system management and balancing

A method and a corresponding apparatus provide for remapping for wear leveling of a memory. The method is implemented as logic and includes the steps of receiving a memory operation, the memory operation including a logical memory address; dividing the logical address into a logical block address portion, a logical line address portion, and a logical subline address portion; translating the logical block address portion into a physical block address; selecting a line remap key; applying the line remap key to the logical line address portion to produce a physical line address; producing a physical subline address portion; and combining the physical block, line, and subline address portions to produce a physical address for the memory operation.

Remapping for memory wear leveling

A system includes a number of hard disk drives and a controller. Each hard disk drive is selected from a number of different hard disk drive types. Each hard disk drive type has a different speed at which the hard disk drives of the hard disk drive type rotate to read and write data. At least one of the hard disk drives is of a different hard disk drive type than at least one other of the hard disk drives. The controller, responsive to a request to write particular data to the hard disk drives, is to select a given hard disk drive of the hard disk drives based on a type of the particular data, and is to write the particular data to the given hard disk drive.

Hard disk drives having different rotational speeds

A method of recovering a value in a data storage system includes maintaining a list of entries corresponding to values that have been inserted into the data storage system, determining whether the values are at an At Maximum Redundancy (AMR) state, and if not, the converging the values to the AMR state.

Recovery procedure for a data storage system

A method is provided for efficiently recovering information in a distributed storage system where a list of values that should be stored on a storage device is maintained. A first convergence round is scheduled to be performed on the list of values to bring each value to an At Maximum Redundancy (AMR) state. A second convergence round is scheduled to be performed on the list by selecting a wait time interval from a predefined range of wait time intervals between starts of convergence rounds.

Efficient failure recovery in a distributed data storage system

A method for measuring consistability of a distributed storage system is disclosed. The method includes determining at least one consistency level that the distributed storage system can provide. A plurality of failure classes can be determined for the distributed storage system. A probability of the distributed storage system to be in each of the plurality of failure classes can be measured. Each failure class can be mapped to the at least one consistency level. The probability of each failure class for each consistency level can be summed to determine an expected portion of time that the distributed storage system provides each consistency level.

Methods of measuring consistability of a distributed storage system

Embodiments include methods, apparatus, and systems for managing jobs in a shared file system. One embodiment includes a method that intercepts file accesses within a job on a client to a storage device in a shared file system, detects when a file associated with the job changes, and sends the client a message of the change.

Managing jobs in shared file systems

A method of caching data in a global cache distributed amongst a plurality of computing devices, comprising providing a global cache for caching data accessible to interconnected client devices, where each client contributes a portion of its main memory to the global cache. Each client also maintains an ordering of data that it has in its cache portion. When a remote reference for a cached datum is made, both the supplying client and the requesting client adjust their orderings to reflect the fact that the number of copies of the requested datum now likely exist in the global cache.

Cooperative caching technique

A system and method for measuring clock skew in a network is disclosed. The method comprises sending an echo message at a periodic rate from a plurality of servers in the network to an anchor server. A reply message can be sent from the anchor server to each server that includes a remote timestamp based on the anchor server clock. The remote timestamp can be recorded at each of the servers. A send timestamp that designates a time the echo message was sent and a receive timestamp that designates a time the reply message was received at the server can then be recorded. An estimated clock time of each server may also be calculated relative to the anchor server using the send and receive timestamps. A clock skew value can be determined by subtracting the estimated clock time of each server from the remote timestamp time. Interpolation can then performed between the clock skew values over a selected portion of the period of time to enable clock skew values to be estimated over the selected portion of time.

Growing community of inventors

Mountain View, CA, United States of America

Eric A Anderson