Abstract: File systems possibly impacted by a bad sector in a disk drive are unmounted. Then the disk drive is scanned in order to identify additional bad sectors, and for each identified bad sector, a logical address of the bad sector is re-vectored to a good sector. An attempt is made to restore the data of each bad sector, and then the file system is checked for consistency. If a bad sector cannot be restored, any application relying on the bad sector is aborted. Once the file system is found to be consistent, the file system is remounted. Re-vectored blocks are reverse mapped to identify damaged or repaired directories and files. Damaged or repaired directories and files are reported to a system administrator, and damaged directories or files of a client are reported to the client.

Abstract: This invention is a system and a method for recovering and repairing a logical volume in a data storage environment using a new architecture. The method of recovering a logical volume enables mounting of a file system by instantiating only a single slice under the sparse volume and instantiating rest of the slices provisioned under the sparse volume in background by a asynchronous recovery process or on-demand by the clients of the file system issuing an I/O on the slice volume. The method of repairing a logical volume provides the ability to regenerate the metadata required to reconstruct the corrupted volume.

Abstract: File systems possibly impacted by a bad sector in a disk drive are unmounted. Then the disk drive is scanned in order to identify additional bad sectors, and for each identified bad sector, a logical address of the bad sector is re-vectored to a good sector. An attempt is made to restore the data of each bad sector, and then the file system is checked for consistency. If a bad sector cannot be restored, any application relying on the bad sector is aborted. Once the file system is found to be consistent, the file system is remounted. Re-vectored blocks are reverse mapped to identify damaged or repaired directories and files. Damaged or repaired directories and files are reported to a system administrator, and damaged directories or files of a client are reported to the client.

Abstract: A file server maintains a production file system supported by a clone volume, and multiple snapshot file systems supported by respective save volumes in a snapshot queue. Before a data block is modified for the first time after creation of the youngest snapshot, the data block is copied from the clone volume to the save volume of the youngest snapshot. A bit map indicates the blocks that have already been copied, and a block map shows the save block address for each corresponding clone block address. When a new snapshot is created, the bit and block maps are converted to a hash index that is kept linked to the save volume of what had been the youngest snapshot. When other than the oldest snapshot file system is deleted, the respective save volume is retained as a hidden object until it becomes the oldest save volume.