Symantec Operating Corporation

Veritas Operating Corporation

Symantec Corporation

Hitachi Data Systems Engineering UK Limited

Hitachi, Ltd.

Symantec Operating Company

Oleg Kiselev

John Colgrove

Ronald S Karr

Anand A Kekre

Craig Harmer

Ron Karr

Thomas Lanzatella

Graham Bromley

Blaine T Cuykendall

Gopal Sharma

Allen Unueco

Niranjan Sanjiv Pendharkar

John A Muth

Steven Michael Umbehocker

Feng Wang

Bo Hong

Santosh Ananth Rao

Michael E Root

Kalaivani Arumugham

Abhay Kumar Singh

Robert Baird

Christopher Youngworth

Poonam P Dhavale

Siddhartha Nandi

Santosh Shankar Rao

Gaurab Paul

David Stephen Hartman

Thomas Andrew Glass

Shantanu Sinha

Ben Bernhard

James Mattly

Raghu Krishnamurthy

Shie-rei Huang

Randy Shingai

John A Colgrove

George Mathew

Par Botes

Angshuman Bezbaruah

Milind Vithal Borate

Ankur P Panchbudhe

Hans Van Rietschote

Deepak Tawri

Scott Douglas Kaiser

Ankur Kemkar

Bob Schatz

Michael Wahl

Deepak K Tawri

Arun M Rokade

Ramon Guillermo Pantin

Qin Xin

Rajesh Bhalerao

Evan L Marcus

Steven Micheal Umbehocker

A cluster system includes a plurality of computing nodes connected to a network, each node including one or more storage devices. The cluster system stores data and at least one of data replicas or erasure-coded segments across the plurality of nodes based on a redundancy policy. Further, configuration information, which may be indicative of a data placement of the data and the data replicas or erasure-coded segments on the plurality of nodes, is provided to each of the plurality of nodes. Additionally, each of the nodes may act as a first node which is configured to determine, upon a change of the redundancy policy, updated configuration information based on the change of the redundancy policy and to send a message including information indicating the change of the redundancy policy to the other nodes of the plurality of nodes.

Data redundancy in a cluster system

In some examples, a distributed system may include a plurality of nodes with a file stored in a file system across the plurality of nodes. One of the nodes may receive a request for location data corresponding to a part of the file. For instance, the location data may be included in a mapping file, and the request may specify an offset of the mapping file. The mapping file may include locations of nodes storing parts of the file in the file system across the plurality of nodes, and the mapping file may have a plurality of parts corresponding to the parts of the file. In response to the request, the node may access the mapping file and send location data corresponding to the offset of the mapping file. The location data may indicate at least one of the nodes storing the part of the file.

Locating file data from a mapping file

A cluster system includes a plurality of computing nodes connected to a network. Each node is configured to access its own storage device, and to send and receive input/output (I/O) operations associated with its own storage device. Further, each node of the plurality of nodes may be configured to have a function of acting as a first node, which sends a first message to other nodes of the plurality of nodes. The first message may include configuration information indicative of a data placement of data on the plurality of nodes in the cluster system according to an event. Following receipt of the first message from the first node, each of the other nodes may be configured to determine, based at least in part on the configuration information, whether data stored on its own storage device is affected by the event.

Data configuration and migration in a cluster system

A distributed system includes a plurality of nodes connected over a network. Each node has a unique node identifier which identifies the node in the distributed system. Tasks are launched from any node in the distributed system and include one or more node identifiers. If a node receives a task including its node identifier, the node executes the task. Each node may store each task in a log. If a node fails, after recovering from the failure, the node queries the distributed system for tasks which were not received and tasks which were not completed due to the failure.

Decentralized distributed computing system

In some examples, a node in a distributed system may receive one or more IP addresses for use with one or more virtual machines. For example, at least one of the received IP addresses may be encoded into a respective MAC address. Further, a hypervisor implemented on the node may configure a virtual machine on the node. For instance, configuring the virtual machine may include passing the encoded MAC address to the virtual machine through the hypervisor. The virtual machine may be configured to decode the IP address from the encoded MAC address, and the IP address is assigned to the virtual machine.

Configuring a virtual machine

A storage system includes a plurality of nodes connected to a network. Each node is capable of performing its own recovery of partially written data and maintaining consistency of the data stored on the storage system. The nodes may independently calculate the location of the data across the nodes and independently balance the data, maintain consistency based on a redundancy policy of the storage system, and migrate data according to a location change. If a node determines that the stored data thereon is incomplete or damaged, the node may reconstruct its respective data from replica data on other nodes. During migration of data between the nodes, I/O processing from a host is not interrupted in some examples.

Independent data integrity and redundancy recovery in a storage system

A log manager may store a validation indicator with each data block of a log entry. The log manager may create a header block for each log entry that may include a validation indicator or tag. Such a validation indicator may be stored within the metadata for each data block. The validation indicator may additionally be stored in the metadata for the header block and it may be stored in header block itself. When recovering such a log, according to some embodiments, the validation indicators for each data block are checked against the validation indicator in the header block.

Recoverable single-phase logging

A system and method for storing data. In one embodiment, a storage system includes a resource manager and a hierarchical entry tree describing storage entities of the storage system. At each given level of the tree higher than the bottom level, metadata entries summarize storage availability at a level below the given level. The resource manager receives a request to store data of a target size at a target location corresponding to a first portion of the entry tree and scans the entry tree to determine if contiguous, free storage entities of the target size are available at the target location. In response to determining that contiguous, free storage entities of the target size are not available at the target location, the resource manager scans portions of the entry tree outside the first portion to identify contiguous, free storage entities of the target size, where it stores the data.

System and method of hierarchical space management for storage systems

Applications executing on various nodes in a distributed storage environment may write data to primary storage and may also replicate the data to secondary storage via a replication target. An interval coordinator may coordinate the periodic saving of checkpoints or snapshots of the replicated data. The interval coordinator may determine the length of consistency intervals between the saving of each of the checkpoints. Writes to the replication target from each of the nodes may be associated with the current consistency interval and, in some embodiments, with a unique per-node sequence number. When transitioning between consistency intervals, each node may be configured to temporarily suspend completion of the writes and to send the replication target a consistency interval marker indicating that the node has completed all writes for the current consistency interval.

System and method for replication using consistency interval markers in a distributed storage environment

A method, system, computer system, and computer-readable medium for maintaining up-to-date, consistent copies of primary data without the need to replicate modified data when the data were modified as a result of an operation that is not an application-driven write operation captured during replication. Selected storage management operations are performed on the primary and secondary data stores at points in time when the data are the same to ensure that the data stored within the data stores remain consistent. These selected storage management operations include operations that produce modified data stored in the primary data store, where a portion of the modified data are not replicated to a secondary node. Other types of storage management operations are selected to be performed on both the primary and secondary data stores, where the operations do not directly change data in the primary data store, but may affect data stored in the primary data store.

Coordinated storage management operations in replication environment

A method, system, and computer-readable medium to maintain consistent, up-to-date copies of primary data. Primary data is maintained on a primary node, and point-in-time snapshots of the primary data are maintained on a secondary or remote node. Read operations can be directed to read some or all data from the remote node. When part of the data on the primary node becomes unavailable due to corruption, device failure, or communication failure, unavailable data can be read from the secondary node. When the determination is made that an unavailable portion of the data exists, a third data storage accessible by the first host can be created. Each subsequent change to the data in the first data storage can be written only to the third data storage. If an updated portion of the data is to be read, the updated portion can be read from the third data storage.

Remote data access for local operations

A system and method for storing data. In one embodiment, a file system includes a hierarchy of nodes partitioned into a plurality of containers. The file system further includes metadata associated with each node. First metadata describes each node's references to other nodes and second metadata identifies each node's parent node. The file system further includes a linkage table associated with each container. Each linkage table comprises entries describing links between a node owned by the associated container and other nodes. In response to detecting that a file system error has occurred, the file system identifies a container which corresponds to the detected error, corrects inconsistencies between the first and second metadata associated with each node owned by the container, and corrects inconsistencies between each of the entries of the linkage table associated with the identified container and the first and second metadata.

Fast connectivity recovery for a partitioned namespace

A set of probabilities may indicate the chance of finding the latest version of a data item in any particular data image layer of a data image. A client may use the set of probabilities to request the data item from one or more layers that have a higher probability of having that version of the data item. A client may query more recently created layers to determine whether they have a version of the data item. If any of the more recently created data image layers has a version of the data item, a client may request the data item from the most recent of the more recently created layers and may discard any data returned from the originally requested layer. A client may update the historical probabilities based on which layers contain versions of the data item.

Probabilistic data locating in sparse data images

A system and method for data storage in an array. A system includes a client coupled to a storage subsystem. The storage subsystem comprises data storage locations addressable as rows and columns in an array. Each column comprises a separate storage device. Each row includes redundant data. For a given row, a coordinating storage device receives data from the client, coordinates computation and storage of redundant data, and forwards data to other storage devices. In response to receiving data targeted for storage in a given storage location, a non-volatile, temporary storage device that is associated with the separate storage device that includes the given storage location buffers the received data. The coordinating storage device conveys a write completion message to the client in response to detecting that the data has been buffered in the non-volatile, temporary storage devices. At least two storage devices are coordinating storage devices in separate rows.

System and method of redundantly storing and retrieving data with cooperating storage devices

A system and method for detecting mirror inconsistencies in a distributed storage environment. Inconsistencies between mirrors may be detected by comparing session tags among individual storage devices. Each data write may include a tag and storage devices may calculate session tags from the write tags. Additionally, a storage device may keep a history including tags from recent writes. When a client sessions ends, a metadata server may compare the respective session tags from different storage devices to determine whether the mirrors are synchronized. If the session tags do not match, the metadata server may examine the metadata histories from the storage devices to determine a cause for the discrepancy in the session tags. If examining the session histories fails to reveal the discrepancy's source, a metadata server may request individual data block checksums from storage devices to attempt a re-synchronization of the mirrored storage devices.

Detecting and repairing inconsistencies in storage mirrors

Growing community of inventors

Palo Alto, CA, United States of America

Oleg Kiselev