Abstract: One embodiment provides a method for storage management in a hierarchical file system that includes creating a structure for the hierarchical file system including a top-file system and sub-file systems that each include files and directories. Directories for the sub-file systems of the hierarchical file system are tracked. A request for creation of a unique directory in the hierarchical file system is received. Upon a request by a particular sub-file system for more inodes without any inodes available, inode numbers are revoked from at least one other sub-file system having unused inodes.

Abstract: Data is migrated from a source storage device to a destination storage device using tape media. Both the source storage device and the destination storage device utilize disk drives to store data. A portion of data is detected migrating to the tape media. Metadata of the portion of data is changed to identify the portion of data as residing on the tape media. A prefetch command for the portion of data is detected. It is determined that the portion of data is stored on the tape media. In response to determining that the portion of data is stored on the tape media, the prefetch command is executing without recalling the portion of data to the disk drives. Instead, the portion of data is read directly from the tape media.

Abstract: The embodiments described herein relate to synchronization of data in a shared pool of configurable computer resources. One or more consistency points are created in a source filesystem. A first consistency point is compared with a second consistency point to detect a directory change at the source filesystem, which includes identifying at least one difference between the first and second consistency points. A file level change associated with an established directory at a target filesystem is identified responsive to the detection of the directory change. A link is established between the source filesystem and the target filesystem, and the established directory is updated based on the file level change.

Abstract: One embodiment provides a method for re-balancing data and metadata across multiple sub-file systems of a file system. The method includes determining sub-file systems including an amount of data that exceeds a threshold. At least one cell in the sub-file systems is identified as a candidate for re-balancing. A re-balance process is performed on the at least one cell that includes performing a flush operation to flush dirty data from file system buffers, copying an inode table for an independent set of files in the at least one cell to a destination sub-file system, notifying an allocation manager for the destination sub-file system of a new storage pool to manage, and performing an un-quiesce operation on I/O operations to each element in the at least one cell.

Abstract: A system facilitates access to data in a network and includes a cache that stores instructions. A processor executes the instructions including: caching processing configured to integrate caching into a local cluster file system, and cache local file data in the cache based on fetching file data on demand from a remote cluster file system. The cache is visible to file system clients as a Portable Operating System Interface (POSIX) compliant file system. Applications execute on a multi-node cache cluster using POSIX semantics via a POSIX compliant file system interface. Data cache is locally and remotely consistent for updates.

Abstract: In one embodiment, a method includes determining a home node that corresponds to gateway (GW) nodes in a clustered file system, each GW node being eligible to process one or more read tasks, determining a peer GW eligibility value for more than one of the GW nodes in the clustered file system eligible to process one or more read tasks, and determining a single GW node from amongst the GW nodes having a highest peer GW eligibility value for each home node. Additionally, the method includes assigning and defining a size for one or more read task items for the GW nodes having the highest peer GW eligibility value for multiple home nodes based on a current dynamic profile of the GW nodes, and distributing workload to the GW nodes according to the size for each of the one or more read task items assigned to the GW nodes.

Abstract: One embodiment provides a method for storage management in a hierarchical file system that includes creating a structure for the hierarchical file system including a top-file system and sub-file systems that each include files and directories. Directories for the sub-file systems of the hierarchical file system are tracked. A request for creation of a unique directory in the hierarchical file system is received. Upon a request by a particular sub-file system for more inodes without any inodes available, inode numbers are revoked from at least one other sub-file system having unused inodes.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical set of file systems and maintaining a corresponding directory in a top-file system and a number of symbolic pointers in the corresponding directory which each point from the corresponding directory to a sub-file system where any portion of the tracked directory resides. If available space in a first sub-file system is below a threshold, the system identifies a second sub-file system with available space above the threshold, wherein the first sub-file system contains a first portion of the directory. If a second portion of the directory does not exist in the second sub-file system, the system creates the second portion of the directory in the second sub-file system and creates a link from the first portion of the directory to the second portion of the directory.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical file system. A request for a unique directory in the hierarchical file system is received. The sub-file system of the hierarchical file system containing the unique directory is provided while ensuring that each directory resides in only one sub-file system. The system also maintains, in a top-file system, a corresponding directory and a symbolic pointer which points from the corresponding directory to a sub-file system where a given directory resides. Creation of new directories in sub-file systems also includes creation of corresponding directories in the top-file system and symbolic pointers from corresponding directory to new directory.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical set of file systems and maintaining a directory while providing the directory is capable of residing in more than one sub-file system within the hierarchical file system. If available space in a first sub-file system is below a threshold, the system identifies a second sub-file system with available space above the threshold, wherein the first sub-file system contains a first portion of the directory. If a second portion of the directory exists in the second sub-file system, the system creates or expands a file in the second portion of the directory, otherwise the system first creates the second portion of the directory in the second sub-file system and then creates a link from the first portion of the directory to the second portion of the directory.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical file system. A request for creation of an additional directory in the hierarchical file system is received. In response to the request, the additional directory is created in a sub-file system of the hierarchical file system while providing that each directory resides in only one sub-file system. If the additional directory is a child directory, the additional directory is created in the sub-file system containing the parent directory of the child directory.

Abstract: Data is migrated from a source storage device to a destination storage device using tape media. Both the source storage device and the destination storage device utilize disk drives to store data. A portion of data is detected migrating to the tape media. Metadata of the portion of data is changed to identify the portion of data as residing on the tape media. A prefetch command for the portion of data is detected. It is determined that the portion of data is stored on the tape media. In response to determining that the portion of data is stored on the tape media, the prefetch command is executing without recalling the portion of data to the disk drives. Instead, the portion of data is read directly from the tape media.

Abstract: Data is migrated from a source storage device to a destination storage device using tape media. Both the source storage device and the destination storage device utilize disk drives to store data. A portion of data is detected migrating to the tape media. Metadata of the portion of data is changed to identify the portion of data as residing on the tape media. A prefetch command for the portion of data is detected. It is determined that the portion of data is stored on the tape media. In response to determining that the portion of data is stored on the tape media, the prefetch command is executing without recalling the portion of data to the disk drives. Instead, the portion of data is read directly from the tape media.

Abstract: A moving weighted average of application bandwidth is calculated based on updates to a first data storage by a first data site. A moving weighted average of transmission bandwidth is calculated based on replication of the updates to a second data storage via a second data site. A next coordinated consistency point is identified and the time remaining before the next consistency point is calculated. An amount of the updates that can be replicated before the next consistency point is determined based on the average transmission bandwidth. A prediction of an amount of additional updates that will be generated on the first data site before the next consistency point is made using heuristics based on the average application bandwidth. When update accumulation combined with the prediction exceeds the amount of updates that can be replicated before the next consistency point, pending updates are flushed to the second data storage.

Abstract: A moving weighted average of application bandwidth is calculated based on updates to a first data storage by a first data site. A moving weighted average of transmission bandwidth is calculated based on replication of the updates to a second data storage via a second data site. A next coordinated consistency point is identified and the time remaining before the next consistency point is calculated. An amount of the updates that can be replicated before the next consistency point is determined based on the average transmission bandwidth. A prediction of an amount of additional updates that will be generated on the first data site before the next consistency point is made using heuristics based on the average application bandwidth. When update accumulation combined with the prediction exceeds the amount of updates that can be replicated before the next consistency point, pending updates are flushed to the second data storage.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical set of file systems and maintaining a directory while providing the directory is capable of residing in more than one sub-file system within the hierarchical file system. If available space in a first sub-file system is below a threshold, the system identifies a second sub-file system with available space above the threshold, wherein the first sub-file system contains a first portion of the directory. If a second portion of the directory exists in the second sub-file system, the system creates or expands a file in the second portion of the directory, otherwise the system first creates the second portion of the directory in the second sub-file system and then creates a link from the first portion of the directory to the second portion of the directory.

Abstract: One embodiment provides a method for file system namespace rebuilding. The method includes creating attribute data structures for a top-file system and sub-file system hierarchy system. The attribute data structures including hierarchy relationship information. The attribute data structures are stored in the sub-file systems. The top-file system namespace is rebuilt by extracting the hierarchy relationship information from an extended attribute of the attribute data structures in each stub of each sub-file system to build a table. The top-file system hierarchy is built one level at a time starting with the root directory having a parent of NULL.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical set of file systems and maintaining a corresponding directory in a top-file system and a number of symbolic pointers in the corresponding directory which each point from the corresponding directory to a sub-file system where any portion of the tracked directory resides. If available space in a first sub-file system is below a threshold, the system identifies a second sub-file system with available space above the threshold, wherein the first sub-file system contains a first portion of the directory. If a second portion of the directory does not exist in the second sub-file system, the system creates the second portion of the directory in the second sub-file system and creates a link from the first portion of the directory to the second portion of the directory.

Abstract: One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical file system. A request for a unique directory in the hierarchical file system is received. The sub-file system of the hierarchical file system containing the unique directory is provided while ensuring that each directory resides in only one sub-file system. The system also maintains, in a top-file system, a corresponding directory and a symbolic pointer which points from the corresponding directory to a sub-file system where a given directory resides. Creation of new directories in sub-file systems also includes creation of corresponding directories in the top-file system and symbolic pointers from corresponding directory to new directory.

Abstract: One embodiment provides a method for re-balancing data and metadata across multiple sub-file systems of a file system. The method includes determining sub-file systems including an amount of data that exceeds a threshold. At least one cell in the sub-file systems is identified as a candidate for re-balancing. A re-balance process is performed on the at least one cell that includes performing a flush operation to flush dirty data from file system buffers, copying an inode table for an independent set of files in the at least one cell to a destination sub-file system, notifying an allocation manager for the destination sub-file system of a new storage pool to manage, and performing an un-quiesce operation on I/O operations to each element in the at least one cell.