Abstract: A method for converting metadata in a hierarchical configuration within a filesystem from a first format to a second format includes reading metadata in the first format within the hierarchical configuration; writing the metadata from the hierarchical configuration into a flat file; and writing the metadata back into the hierarchical configuration, the metadata being in the second format. The method can also include increasing the size of each of a first inode and a second inode within a first inode chunk in the filesystem, assigning the first inode to the first inode chunk, and assigning the second inode to a second inode chunk.

Abstract: Example apparatus, methods, data structures, and computers defragment unallocated space in a storage associated with an extent based file system. One example method locates a first unallocated area having a desired size and a desired location to receive an extent from a first end of an allocated area in the storage. The example method then swaps the extent from the first end of the allocated area with the first unallocated area. The example method also locates a second unallocated area having a desired size and a desired location to receive an extent from a second opposite end of the allocated area in the storage. The example method then swaps the extent from the second end of the allocated area with the second unallocated area. The example method may continue to swap until no more suitable unallocated regions are available to receive an extent sliced off an allocated area.

Abstract: Example systems, methods, and apparatus economize generating and processing incremental journal files while maintaining internal consistency. One example method determines whether a sequence number associated with a first inode description in a disaster recovery (DR) journal entry is out of sequence with a second corresponding inode description in a DR metadump. The example method controls a DR journal process to provide a file system inconsistency signal and to suspend application of the DR journal entry to the DR metadump. The suspending and signaling can occur upon determining that a first access time independent verification code computed from the first inode description does not match a second access time independent verification code computed from the second inode description.

Abstract: Example apparatus, methods, and computers prevent a split brain scenario in a pair of high availability servers by maintaining single writer access to a resource. One example method includes monitoring control of an arbitration (ARB) block by an active file system manager (FSM). An active file system portmapper (FSMPM) simultaneously requests permission from a standby FSM to restart a dead-man timer. The active FSM attempts to maintain control of the ARB block before expiration of the dead-man timer. If the active FSM is unable to maintain control of the ARB block before expiration of the dead-man timer, a hardware reset of an apparatus running the active FSM is forced. Therefore, the active FSMPM and standby FSM negotiate for additional time to maintain control of the ARB block to maintain single writer access and avoid unnecessary hardware resets.

Abstract: Example apparatus, methods, and computers prevent a split brain scenario in a pair of high availability servers by maintaining single writer access to a resource by controlling the resource according to a timer bounded arbitration protocol that controls self-termination of a writer process. One example method includes monitoring control of an arbitration (ARB) block by an active file system manager (FSM) and selectively causing a selection of a standby metadata controller (MDC) when control of the ARB block does not satisfy the timer bounded ARB protocol. The example method also includes selectively forcing a hardware reset of an apparatus running the active FSM and selectively establishing an FSM on a selected redundant MDC as a replacement FSM.

Abstract: A method for converting metadata in a hierarchical configuration within a filesystem from a first format to a second format includes reading metadata that is in the first format within the hierarchical configuration; writing the metadata from the hierarchical configuration into a flat file; and writing the metadata back into the hierarchical configuration, the metadata being in the second format. The method can also include increasing the size of each of a first inode and a second inode within a first inode chunk in the filesystem, assigning the first inode to the first inode chunk, and assigning the second inode to a second inode chunk.