Hitachi Data Systems Engineering UK Limited

Bluearc UK Limited

Hitachi, Ltd.

Madge Networks Limited

Hitachi Data Engineering UK Limited

Trevor Edward Willis

Christopher J Aston

Simon L Benham

Geoffrey S Barrall

Mark Stephen Laker

Michael Cooper

Jonathan Meyer

John Winfield

Mitsuo Hayasaka

Yuko Matsui

Francesco Lacapra

Fiorenzo Cattaneo

Neil Berrington

Carlo F Garbagnati

Shmuel Shottan

Simon Latimer Benham

Martin A Dorey

Jonathan Mark Smith

Adrian Michael Suggett

The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures, including obtaining the root node and/or nodes of the at least one tree level of the metadata structure maintained in the cache memory from the cache memory and obtaining at least one node of another tree level of the metadata structure from the one or more storage devices.

Data storage system, process and computer program for such data storage system for reducing read and write amplifications

The data storage system includes one or more storage apparatuses and a file system server connected to the one or more storage apparatuses and to one or more host computers. Write operations are controlled by providing a free space object which stores a plurality of indicators, each indicator being associated with one of a plurality of storage units for storing data units in the one or more storage apparatuses and each indicator indicating whether the associated storage unit is free or used, executing a read-ahead examination which comprises examining a set of indicators of the free space object for identifying one or more used storage units associated with indicators of the set, in particular for observing a fragmentation status of the storage units associated with the indicators of the set, and executing an allocation examination which comprises examining one or more indicators.

Computer program product, method, apparatus and data storage system for controlling write operations in the data storage system

The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures.

Available storage locations are identified by searching through a free blocks object non-sequentially. The free blocks object may be logically divided into sections, and the sections may be searched non-sequentially. Each section may be logically divided into a number of sub-sections, and the sub-sections of the various sections may be searched non-sequentially. A new section may be added to the free blocks object, and the added section may be searched until a predetermined threshold or condition is reached, at which point non-sequential searching may begin or resume.

Dynamic write balancing in a data storage system

Apparatus for managing a plurality of root nodes may include a file server coupled to a storage device, wherein a first root node is operable to identify a previous version of an object of a file system and to relate to a plurality of data blocks forming a portion of the object, a second root node is operable to identify a current version of the object and to relate to a data block of the plurality of data blocks and a new data block of the object, and the storage device is operable to store the plurality of data blocks and the new data block. Apparatus for managing a plurality of root nodes alternatively may include a file system board operable to manage a plurality of root nodes, a first root node being operable to identify the a previous version of a file system and to relate to a plurality of data blocks of the file system, and a second root node being operable to identify the a current version of the file system and to relate to a data block of the plurality of data blocks and a new data block of the file system.

Apparatus for managing a plurality of root nodes for file systems

Apparatus includes a file server node having (i) a first interface operable to communicate with a network and receiving a network request via network, (ii) a non-volatile memory operable to temporarily store a request related to the network request received by the first interface, (iii) a second interface operable to be coupled to the storage device for storing the request, and (iv) a non-volatile memory processing module, coupled to the first interface, the non-volatile memory and the second interface, and operable to be coupled to another file server node, so that the request can be sent to the non-volatile memory, the second interface and the another file server node after the non-volatile memory processing module receives the file system request.

File server node with non-volatile memory processing module coupled to cluster file server node

A multi-tiered filesystem integrates multiple types of storage devices into a contiguous filesystem storage space having regions associated with two or more tiers of storage.

Multi-tiered filesystem

A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Distributed file system and method

Apparatus for managing plural versions of a root node for an object of a file system manages an update data of a first version of the plural versions of the root node in a status in which (i) data of a second version of the plural versions of the root node is written from the second storage of the file server to the first storage and (ii) a new checkpoint, capable of being used when the object of the file system is recovered, is taken. The apparatus also manages an update data of the second version of the plural versions of the root node in another status in which (iii) data of the first version of the plural versions of the root node is written from the second storage of the file server to the first storage and (iv) a next new checkpoint is taken.

Apparatus for managing plural versions of a root node for an object of a file system

A hardware-based file system includes multiple linked sub-modules that perform functions ancillary to client data handling. Each sub-module is associated with a metadata cache. A doubly-rooted structure is used to store each file system object at successive checkpoints. Metadata is stored within an object and/or as a separate object. Provisions are made for allocating sparse objects. A delayed write feature is used for writing certain objects into non-volatile storage. Checkpoints can be retained as read-only versions of the file system. Modifications to the file system are accomplished without affecting the contents of retained checkpoints. The file system can be reverted to a retained checkpoint. Multiple file servers can be interconnected as a cluster, and each file server stores requests from another file server. Interconnections between file servers can be dynamically modified. A distributed locking mechanism is used to control access to file system objects stored by the file servers.

Apparatus and method for hardware-based file system

An apparatus in one embodiment handles service requests over a network, wherein the network utilizes a protocol. In this aspect, the apparatus includes: a network subsystem for receiving and transmitting network service requests using the network protocol; and a service subsystem, coupled to the network subsystem, for satisfying the network service requests. At least one of the network subsystem and the service subsystem is hardware-implemented; the other of the network subsystem and the service subsystem may optionally be hardware-accelerated. A variety of related embodiments are also provided, including file servers and web servers.

Apparatus and method for hardware implementation or acceleration of operating system functions

A file system adapter card that may be plugged into a host computer system for providing hardware-based file system accesses outside the purview of a host operating system running on the host computer system. The file system adapter card includes a hardware-implemented or hardware-accelerated file service subsystem and a computer bus that permits a host computer system to communicate directly with the file service subsystem for providing file service requests and receiving file service responses. The file service subsystem includes dedicated hardware that operates outside the immediate control of a host operating system, including specialized circuitry for performing at least one major subsystem function.

Growing community of inventors

Buckinghamshire, United Kingdom

Trevor Edward Willis