International Business Machines Corporation

Janet Elizabeth Adkins

Joon Chang

Manoj N Kumar

David Jones Craft

Ninad S Palsule

Andrew N Solomon

Matthew Todd Brandyberry

Mark Allen Grubbs

Thomas Stanley Mathews

Grover Herbert Neuman

Frank L Nichols, Iii

Gokul Bhargava Kandiraju

Neeta Garimella

Robert K Gjertsen

Ashley D Lai

A method, system, and program product is provided for splitting a clone object from a parent object when the clone object includes at least one snapshot. A mapping is created of a source data block from the parent object to a destination data block in the clone object. A creation generation in the mapped source data block is compared to an isolate generation in the destination data block in the clone object. Inherited data blocks in the clone object are isolated from the parent object, based on the creation generation differing from the isolate generation. The destination block is updated with the mapping information.

Splitting a clone having snapshots from a parent

Mechanisms are provided for importing pre-existing data into a storage system utilizing a current storage management system that is different from an original storage management system used to create the pre-existing data. One or more data storage devices are integrated into the storage system in-place without modification of the pre-existing data stored on the one or more data storage devices. Metadata for the pre-existing data is created based on a linear progression of data in the pre-existing data. Read access requests targeting the pre-existing data are executed using the created metadata. Write access requests targeting the pre-existing data are executed by redirecting the write access requests to a copy of the pre-existing data created in another storage location.

Importing pre-existing data of a prior storage solution into a storage pool for use with a new storage solution

A method includes determining, by a processor, that a write request indicates a clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. The method includes determining that the data block at a current location cannot be modified. In response to a determination that the data block at the current location cannot be modified, the method includes implementing the write request with respect to the data block at a different location and indicating that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

File cloning across different filesets

A technique for operating a client node in a clustered file system includes allocating a number of blocks during a first time window and tracking the number of blocks allocated during the first time window. The technique further includes transmitting a block allocation request to a server node of the clustered file system for a number of requested blocks in response to a number of free blocks in a client-side block map reaching a first threshold value. In this case, the number of the requested blocks is based on the number of blocks allocated by the client node during the first time window.

Activity-based block management of a clustered file system

Activity-based block management of a clustered file system using client-side block maps

A method including creating a commit-in-progress context from a copy of a data object in a redirect-on-write file system; and begin storing the commit-in-progress context in a persistent storage device. The method further includes, while storing the commit-in-progress context in the persistent storage device: receiving a notification of a pending modification to the first data object, creating an update-in-progress context from a copy of the commit-in-progress context, and begin applying the modification to the update-in-progress context. The method further includes detecting that a connectivity error has occurred between the commit-in-progress context and the storage device, and in response, identifying whether the commit-in-progress context is successfully stored in the storage device. In response to identifying that the commit-in-progress context is not successfully stored: aborting the storing of the commit-in-progress context, assigning a new commit-in-progress context, and begin storing the new commit-in-progress context.

Merging multiple contexts to manage consistency snapshot errors

After a clone file is created from a file, a write request targeting the clone file can be handled. It is determined that the write request indicates the clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. It is then determined that the data block at a current location cannot be modified. The write request is implemented with respect to the data block at a different location. It is indicated that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Embodiments include a computer program product and an apparatus for cloning files across different filesets and maintaining the clone files. After a clone file is created from a file, a write request targeting the clone file can be handled. It is determined that the write request indicates the clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. It is then determined that the data block at a current location cannot be modified. The write request is implemented with respect to the data block at a different location. It is indicated that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

A method includes initiating committing to persistent storage of a current consistency snapshot of a plurality of data objects in a redirect-on-write file system. Each of the plurality of data objects has a first copy of at least two copies of the data having a first context of at least two contexts. The method includes receiving, during committing to storage of the current consistency snapshot, an update to a data object of the plurality of data objects. The method also includes responsive to receipt of the update to the data object, creating a second copy of data of the data object from the first copy. The second copy of the data has a second context of the at least two contexts. The method includes responsive to receipt of the update to the data object, updating, based on the update, the second copy of the data of the data object.

Multiple contexts in a redirect on write file system

One embodiment is for using a sparse file as a clone. The method includes creating, by an application associated with a computer system, a snapshot of a file, such as an individual file, a collection of files, file system, directories, and so forth. Further, the method includes requesting, by the application, a clone of that created snapshot. Further still, the method includes generating, by the application, an empty sparse having at least one inode identifying the empty sparse file as the clone and pointing to the snapshot associated with the clone. Thereby, the requested clone is created using the created sparse file, which begins as an empty sparse file.

Using a sparse file as a clone of a file

Management of a file hierarchy for a clustered file system can be distributed across nodes of the cluster. A cluster file hierarchy is accessed to determine location of a file in response to a request to write to a file. A first node maintains the cluster file hierarchy. It is determined that management of a fileset object, which represents a fileset that includes the file, has been delegated to a second node based, at least in part, on said accessing the cluster file hierarchy. A node file hierarchy maintained by the second node is accessed responsive to determining the delegation. The cluster file hierarchy represents filesets of the clustered file system and the node hierarchy represents a subset of one or more of the filesets. Location of the file is determined based, at least in part, on said accessing the node file hierarchy.

Distributed file hierarchy management in a clustered redirect-on-write file system

In a cluster that distributes fileset management, fileset managers will maintain a free block map and an in-flight block map to allocate blocks to clients writing to a relevant fileset. A fileset manager managing free block allocation for cluster clients that write to a fileset managed by the fileset manager. Since a clustered file system manager manages an initial free block map for the cluster ('cluster free block map'), the clustered file system manager provisions free blocks to fileset managers from the cluster free block map. The fileset manager then allocates free blocks from the provisioned free blocks to cluster clients that write to the fileset managed by the fileset manager.

Distributed free block map for a clustered redirect-on-write file system

Embodiments include a method for removing a file within a redirect-on-write file system. In some embodiments, a file removal operation is detected in a file management unit, which resides in a memory unit. It is then determined that the number of free data blocks in the persistent storage is below a minimum threshold. The file removal operation is written to a log used for storing system operations. A file management unit is notified of the successful write of the file removal operation to the log used for storing system operations. The data blocks are moved from the file selected for removal to a list of free data blocks. The indirect blocks from the file selected for removal are moved to a data block removal list.

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Austin, TX, United States of America

Janet Elizabeth Adkins