Abstract: A processor selects file system metadata. A processor identifies each unit of data in a file system. The processor determines if the unit of data contains file system metadata. The processor writes a unit of data of metadata to a diagnostic file system, provided it was determined that the unit of data contains file system metadata. The processor then determines if the unit of data contains user data. If the unit of data contains user data, the processor writes a sparse object to the diagnostic file.

Abstract: A processor selects file system metadata. A processor identifies each unit of data in a file system. The processor determines if the unit of data contains file system metadata. The processor writes a unit of data of metadata to a diagnostic file system, provided it was determined that the unit of data contains file system metadata. The processor then determines if the unit of data contains user data. If the unit of data contains user data, the processor writes a sparse object to the diagnostic file.

Abstract: A temporary file is identified. The temporary file includes a data block containing a first file image. A determination is made whether the temporary block has been included in a previous snapshot. Responsive to receiving a modification of the temporary block that has been included in the previous snapshot, a modified first image is created. The modified image is stored in the original file block, and the original image is copied to a newly allocated block. The original first block is updated to include a reference to the second block.

Abstract: A system for managing a file system. In response to a user selecting an image of the file system to perform a rollback operation, each data block in the file system that is owned by the image is searched for. Then, it is determined whether a data block owned by the image is marked in a first map and a second map. In response to determining that the data block owned by the image is marked in the first map and the second map, the data block is marked in a third map. In response to determining that the data block owned by the image is marked in the third map, a new data block is allocated in the file system. Subsequently, data from the data block owned by the image is copied to the new data block in the file system prior to performing the rollback operation to avoid a collision that causes data corruption.

Abstract: A system for managing a file system. In response to a user selecting an image of the file system to perform a rollback operation, each data block in the file system that is owned by the image is searched for. Then, it is determined whether a data block owned by the image is marked in a first map and a second map. In response to determining that the data block owned by the image is marked in the first map and the second map, the data block is marked in a third map. In response to determining that the data block owned by the image is marked in the third map, a new data block is allocated in the file system. Subsequently, data from the data block owned by the image is copied to the new data block in the file system prior to performing the rollback operation to avoid a collision that causes data corruption.

Abstract: An operating system creates a current sparse object in a diagnostic file system. Then the operating system processes a change to data contained in a block. The operating system determines if the change is to a metadata block. The operating system encodes the change in a journal log, in response to a determination that the change is to a metadata block. In addition, the operating system writes the block to the current sparse object, in response to a determination that the change is to a metadata block.

Abstract: A temporary file is identified. The temporary file includes a data block containing a first file image. A determination is made whether the temporary block has been included in a previous snapshot. Responsive to receiving a modification of the temporary block that has been included in the previous snapshot, a modified first image is created. The modified image is stored in the original file block, and the original image is copied to a newly allocated block. The original first block is updated to include a reference to the second block.

Abstract: A processor selects file system metadata. A processor identifies each unit of data in a file system. The processor determines if the unit of data contains file system metadata. The processor writes a unit of data of metadata to a diagnostic file system, provided it was determined that the unit of data contains file system metadata. The processor then determines if the unit of data contains user data. If the unit of data contains user data, the processor writes a sparse object to the diagnostic file.

Abstract: A system and method in a data processing system for recovering data in a file system. A request to modify a data block in the file system is detected. In response to detecting the request to modify the data block, metadata describing the data block in the file system is written in a log. In response to detecting an error during the writing of the metadata, an error counter is incremented. Finally, in response to a request to recover the data in the file system, the metadata is read only if the error counter is less than or equal to a predetermined value.

Abstract: A processor selects file system metadata. A processor identifies each unit of data in a file system. The processor determines if the unit of data contains file system metadata. The processor writes a unit of data of metadata to a diagnostic file system, provided it was determined that the unit of data contains file system metadata. The processor then determines if the unit of data contains user data. If the unit of data contains user data, the processor writes a sparse object to the diagnostic file.

Abstract: A system for managing a file system. In response to a user selecting an image of the file system to perform a rollback operation, each data block in the file system that is owned by the image is searched for. Then, it is determined whether a data block owned by the image is marked in a first map and a second map. In response to determining that the data block owned by the image is marked in the first map and the second map, the data block is marked in a third map. In response to determining that the data block owned by the image is marked in the third map, a new data block is allocated in the file system. Subsequently, data from the data block owned by the image is copied to the new data block in the file system prior to performing the rollback operation to avoid a collision that causes data corruption.

Abstract: A method, apparatus, and computer instructions for managing data in a file system in a data processing system. A request to modify a data block in the file system is detected during file system recovery time. In response to detecting the request, metadata is written to describe the data block into a snapshot image. The data is copied for the data block in the file system to the snapshot image. The data block is modified in the file system after the data is copied into the snapshot image. The snapshot image may be used to return the file system to a state prior to modifying the data block in the file system.

Abstract: A processor selects file system metadata. A processor identifies each unit of data in a file system. The processor determines if the unit of data contains file system metadata. The processor writes a unit of data of metadata to a diagnostic file system, provided it was determined that the unit of data contains file system metadata. The processor then determines if the unit of data contains user data. If the unit of data contains user data, the processor writes a sparse object to the diagnostic file.

Abstract: An apparatus, system, and method are disclosed for differential data backup using snapshot on-write data. A snapshot module maintains an on-write data structure that captures a point-in-time or temporal instance of a data set by tracking modifications to data blocks of a data set. A backup module copies the data set to a backup data storage device as a full data set backup. In addition, the backup module copies each modified data block indicated by the on-write data structure and a differential time stamp to the backup data storage device as a differential data set backup. The full data set backup and one or more differential data set backups form a plurality of temporal instances of the data set. In one embodiment, a restore module recovers a selected instance of the data set responsive to receiving a restore command by copying the full data set backup to a target data storage device.

Abstract: A system and method in a data processing system for recovering data in a file system. A request to modify a data block in the file system is detected. In response to detecting the request to modify the data block, metadata describing the data block in the file system is written in a log. In response to detecting an error during the writing of the metadata, an error counter is incremented. Finally, in response to a request to recover the data in the file system, the metadata is read only if the error counter is less than or equal to a predetermined value.

Abstract: A method, apparatus, and computer instructions for managing data in a file system in a data processing system. A request to modify a data block in the file system is detected during file system recovery time. In response to detecting the request, metadata is written to describe the data block into a snapshot image. The data is copied for the data block in the file system to the snapshot image. The data block is modified in the file system after the data is copied into the snapshot image. The snapshot image may be used to return the file system to a state prior to modifying the data block in the file system.