Abstract: Embodiments of the invention relate to storage allocation in a storage system. One embodiment includes adaptively determining, by a storage device processor, a region height across disk spaces of a group of storage devices that is proportional to a number of connected storage devices. The storage device processor adaptively determines a region width across the disk spaces for the group of storage devices that is inversely proportional to a number of nodes sharing a particular storage device.

Abstract: Embodiments of the invention relate to storage allocation in a storage system. One embodiment includes generating a request for storage space allocation in a particular storage device by a first node. An owner node associated with the particular storage device is determined by a first allocation client associated with the first node. The request is sent by the first allocation client to a second allocation client associated with the owner node. A storage device allocation region of the particular storage device is created, the allocation region comprising a height proportional to storage devices the owner node and the second allocation client are coupled with, and a width that is inversely proportional to a number of nodes sharing the particular storage device.

Abstract: Aspects of the invention are provided to support partial file caching on a file system block boundary. All read requests are converted so that offset and count are aligned on a block boundary. Data associated with read requests is first satisfied from local cache, with cache misses supported with a call to persistent or remote system. Similarly, for a write request, any partial blocks are aligned to the block boundary. Data associated with the write request is performed on local cache and placed in a queue for replay to the persistent or remote system.

Abstract: A method for accessing data stored in a distributed caching storage system containing a home cluster and a secondary cluster is provided. A first copy of a file is stored on the home cluster and a second copy of the file is stored on the secondary cluster. The second copy of the file is associated with an inode data structure having a consistency attribute. An input/output request is received directed to the file and indicates that file is in an inconsistent state by updating the inode's consistency attribute. The first copy and the second copy of the file is updated according to the received input/output request and it is determined whether the first copy and the second copy were updated successfully. The maintaining of the inode's consistency attribute is indicative of the inconsistent state of the file.

Abstract: Aspects of the invention are provided to support partial file caching on a file system block boundary. All read requests are converted so that offset and count are aligned on a block boundary. Data associated with read requests is first satisfied from local cache, with cache misses supported with a call to persistent or remote system. Similarly, for a write request, any partial blocks are aligned to the block boundary. Data associated with the write request is performed on local cache and placed in a queue for replay to the persistent or remote system.

Abstract: A computer-implemented method enables efficient tracking of fileset IDs and inode utilizing a fileset mask and an internal inode mask. A utility dynamically updates the fileset mask and the internal inode mask to enable mapping of the number of one (1) bits in the fileset mask to a fileset identifier (ID) and mapping of the one bits in the inode mask to an inode number for the fileset, as either the number of filesets or the number of inodes required per filesets increases above a next power of two threshold. The one bits within the fileset mask and the internal inode mask are disjoint relative to each other. An external inode number is mapped to a corresponding fileset and to a corresponding inode number by concatenating individual bits of the external inode number corresponding to each one (1) bit within the fileset mask and the inode mask.

Abstract: Embodiments of the inventions relate to granular management of data storage blocks in a data storage system. In one aspect, status values are employed to track “used”, “free”, and “claimed free” storage blocks. A storage block having stored data is identified as used, a storage block available to store data is identified as free, and a storage block having previously stored data removed that has not been reclaimed is identified as claimed free. These values are maintained on a map to track each data block within the data storage system. Available claimed free data blocks are prioritized for data block allocation over available free data blocks for efficient storage, including enabling efficient reclamation of data blocks and minimizing data movement needed for reclamation-oriented de-fragmentation.

Abstract: A method for accessing data stored in a distributed caching storage system containing a home cluster and a secondary cluster is provided. A first copy of a file is stored on the home cluster and a second copy of the file is stored on the secondary cluster. The second copy of the file is associated with an inode data structure having a consistency attribute. An input/output request is received directed to the file and indicates that file is in an inconsistent state by updating the inode's consistency attribute. The first copy and the second copy of the file is updated according to the received input/output request and it is determined whether the first copy and the second copy were updated successfully. The maintaining of the inode's consistency attribute is indicative of the inconsistent state of the file.

Abstract: Embodiments of the invention relate to supporting coordinated access to a file system's shared disk storage subsystem using an automatic alignment of a parallel file access protocol and metadata management on a per object basis. A file server (among servers in the cluster) receives a client's request to access a file stored by the file system in the storage subsystem using a parallel file access protocol. If the file system has selected a file server to serve as a metadata manager of said file, the file server uses the selected file server to coordinate access to the file's metadata. If the file system has not selected a file server to serve as the metadata manager of the file, the file system selects the file server that received said request as the metadata manager for said file until a file close request operation is received.

Abstract: Embodiments of the inventions relate to granular management of data storage blocks in a data storage system. In one aspect, status values are employed to track “used”, “free”, and “claimed free” storage blocks. A storage block having stored data is identified as used, a storage block available to store data is identified as free, and a storage block having previously stored data removed that has not been reclaimed is identified as claimed free. These values are maintained on a map to track each data block within the data storage system. Available claimed free data blocks are prioritized for data block allocation over available free data blocks for efficient storage, including enabling efficient reclamation of data blocks and minimizing data movement needed for reclamation-oriented de-fragmentation.

Abstract: Embodiments of the inventions relate to granular management of data storage blocks in a data storage system. In one aspect, status values are employed to track “used”, “free”, and “claimed free” storage blocks. A storage block having stored data is identified as used, a storage block available to store data is identified as free, and a storage block having previously stored data removed that has not been reclaimed is identified as claimed free. These values are maintained on a map to track each data block within the data storage system. Available claimed free data blocks are prioritized for data block allocation over available free data blocks for efficient storage, including enabling efficient reclamation of data blocks and minimizing data movement needed for reclamation-oriented de-fragmentation.

Abstract: An identification system that may be used in heterogeneous computing environments provides a fail-free path to providing identifiers from a single canonical namespace. Objects or gateways requiring an identifier for access are accessed using an identifier for the canonical namespace. If an entity requests access using an identifier from another namespace, an external database is consulted to determine if a mapping exists for the identifier to another identifier the canonical namespace. If no mapping exists, or the external database is unavailable, then an identifier is automatically generated in the canonical namespace and is used for the access. An internal database is updated with the automatically generated identifier, providing a mechanism to add mappings without administrative intervention. To access resources requiring an identifier from another particular namespace, a canonical namespace identifier may be mapped to another identifier in the particular namespace, or a generic identifier may be used.

Abstract: Embodiments of the invention relate to storage allocation in a storage system. One embodiment includes generating a request for storage space allocation in a particular storage device by a first node. An owner node associated with the particular storage device is determined by a first allocation client associated with the first node. The request is sent by the first allocation client to a second allocation client associated with the owner node. A storage device allocation region of the particular storage device is created, the allocation region comprising a height proportional to storage devices the owner node and the second allocation client are coupled with, and a width that is inversely proportional to a number of nodes sharing the particular storage device.

Abstract: An identification system that may be used in heterogeneous computing environments provides a fail-free path to providing identifiers from a single canonical namespace. Objects or gateways requiring an identifier for access are accessed using an identifier for the canonical namespace. If an entity requests access using an identifier from another namespace, an external database is consulted to determine if a mapping exists for the identifier to another identifier the canonical namespace. If no mapping exists, or the external database is unavailable, then an identifier is automatically generated in the canonical namespace and is used for the access. An internal database is updated with the automatically generated identifier, providing a mechanism to add mappings without administrative intervention. To access resources requiring an identifier from another particular namespace, a canonical namespace identifier may be mapped to another identifier in the particular namespace, or a generic identifier may be used.

Abstract: Embodiments of the invention relate to supporting coordinated access to a clustered file system's shared disk storage subsystem by using dynamic creation of file access layout for different workloads and access patterns. Active file servers in the cluster have equivalent access to shared data of said file system. In one embodiment, a particular file server in the cluster is configured to coordinate the file system's layout. The particular file server, in response to a particular client's request for a layout of a file stored by said file system in said subsystem determines a file access layout for a parallel file access protocol to use when servicing an I/O request by said client, marks said layout as active for the client, and sends the layout to the client. The file access layout is determined based on one or more of current file system resources, a specific workload type and a specific byte-range of the file included in the client request, and properties of the file.

Abstract: Embodiments of the invention relate to coordinated access to a clustered file system's shared storage subsystem using a shared-lock architecture. A particular file server is configured to coordinate the file system's file access layout particular server, in response to a client's file access layout request for byte-ranges of a file stored in the storage subsystem being received by a file server in cluster and sent to said particular server, generates a file access layout of a set of file servers for a parallel file access protocol to use and byte ranges of the file that particular individual file servers to use, to service an I/O request for the file. The file server (that received the request), sends the generated file access layout to said client, and requests coordinated access to said file from the particular server in response to receiving an I/O request to byte-ranges of said file.

Abstract: Embodiments of the invention relate to supporting coordinated access to a file system's shared disk storage subsystem using an automatic alignment of a parallel file access protocol and metadata management on a per object basis. A file server (among servers in the cluster) receives a client's request to access a file stored by the file system in the storage subsystem using a parallel file access protocol. If the file system has selected a file server to serve as a metadata manager of said file, the file server uses the selected file server to coordinate access to the file's metadata. If the file system has not selected a file server to serve as the metadata manager of the file, the file system selects the file server that received said request as the metadata manager for said file until a file close request operation is received.

Abstract: Asynchronous file operations in a scalable multi-node file system cache for a remote cluster file system, is provided. One implementation involves maintaining a scalable multi-node file system cache in a local cluster file system, and caching local file data in the cache by fetching file data on demand from the remote cluster file system into the cache over the network. The local file data corresponds to file data in the remote cluster file system. Local file information is asynchronously committed from the cache to the remote cluster file system over the network.

Abstract: Asynchronous file operations in a scalable multi-node file system cache for a remote cluster file system, is provided. One implementation involves maintaining a scalable multi-node file system cache in a local cluster file system, and caching local file data in the cache by fetching file data on demand from the remote cluster file system into the cache over the network. The local file data corresponds to file data in the remote cluster file system. Local file information is asynchronously committed from the cache to the remote cluster file system over the network.

Abstract: A method for avoiding directory conflicts across a file system having multiple nodes with one node representing a token manager. For each directory, at least one metanode responsible for directory updates. The method involving obtaining a name-based lock on a filename. Querying the token manager for a lock token. If a new token is obtained, sending a Remote Procedure Call (RPC) to the metanode to obtain matching directory entries, and caching the result of the RPC so that subsequent operations on that filename can be satisfied without additional messages sent to the metanode. Updating a cached directory block in memory by creating a new directory entry in the block or deleting an existing directory entry from the block. Information regarding the updating is sent to the metanode on one of: periodic schedule, a subsequent synchronization event, or when the name-based lock token is revoked.