Abstract: A storage system includes a distributed file system. An attribute of a particular entity in the file system relates to a snapshot. In response to an operation in the storage system, it is determined whether the snapshot attribute is to be propagated to another entity of the file system.

Abstract: A file server is provided for use in an association of devices that implements a distributed-file system, the association of devices including file servers that each are configured to control separate segments of the distributed-file system.

Abstract: An exemplary embodiment of the present invention provides a method of processing a file system transaction in a distributed file system. The method includes receiving a transaction request from a computer, wherein the transaction request includes file data to be stored and a first segment identifier that determines a destination of the file data. The method also includes generating a first distributed journal record corresponding to the file data. The method also includes generating a first file operation request based, at least in part, on the transaction request. The method also includes sending the first file operation request to a first segment server corresponding to the first segment identifier, wherein the first segment server generates a second distributed journal record corresponding to the file data on a memory device associated with the first segment server.

Abstract: Embodiments described herein describe a file server used in an association with devices to implement a distributed-file system. The file server includes processor that is operative to store a first shadow tree entry providing a pointer to a file system object, where the first shadow tree entry provides an alternative to a first remote ancestor directory to access the file system object in the distributed file system.

Abstract: A method of performing a file system consistency check in a distributed, segmented file system, includes: analyzing primary objects of a first segment of the file system to determine if a first primary object points to a second primary object of a second segment separate from the first segment, storing, if the first primary object points to the second primary object of the second segment, a first indication indicating that the first primary object points to the second primary object of the second segment, the first indication indicating an expected location of the second primary object; analyzing a shadow directory of the selected segment to determine an expected location of a third primary object, and an expected pointer of the third primary object indicative of a location and a name of a fourth primary object, the third primary object being contained in a segment other than the first segment; and storing a second indication indicating the expected location of the third primary object and the expected pointe

Abstract: A system for implementing a distributed, segmented file system includes file servers that each are configured to control separate segments of the distributed-file system, the file servers including: a memory interface configured to communicate with a memory storing at least one of the segments of the distributed file system; a communication interface coupled to at least another of the file servers; and a processor coupled to the memory interface and the communication interface and configured to control, read, and write to file system objects stored in the memory. The system further includes means for transferring permission for access to a requested file system object from an owner server currently controlling a segment where a requested object resides to an access-requesting server.

Abstract: An exemplary embodiment of the present invention provides a method of processing a file system transaction in a distributed file system. The method includes receiving a transaction request from a computer, wherein the transaction request includes file data to be stored and a first segment identifier that determines a destination of the file data. The method also includes generating a first distributed journal record corresponding to the file data. The method also includes generating a first file operation request based, at least in part, on the transaction request. The method also includes sending the first file operation request to a first segment server corresponding to the first segment identifier, wherein the first segment server generates a second distributed journal record corresponding to the file data on a memory device associated with the first segment server.

Abstract: A system includes storage configured to store file system entities, including directories and files, residing in segments of a distributed, segmented single file system, file servers configured to implement the single file system with separate ones of the file servers controlling metadata of separate ones of the segments, and a controller configured to control storage of files in the file system such that for a master file stored in a first segment, a first replica of the master file will be stored in a second segment that is physically separate from the first segment, the controller being further configured to control storage of directories in the file system such that a single directory will include identifiers for the master file and the first replica.

Abstract: An apparatus in a first device of an association of devices includes a processor configured to: communicate with a storage device storing segments of a distributed, segmented single first file system including file system entities residing in segments and including at least portions of one of files and directories, the association of devices including file servers that control metadata of separate segments of the single first file system, including metadata of file system entities residing in the segments; communicate with a backup module configured to backup file system data of a second file system different from a distributed, segmented file system; analyze data in the single first file system to determine data associated with different segments of the single first file system; and present data from the single first file system to the backup module in accordance with what data belong to which segment of the single first file system.

Abstract: A method of performing a file system consistency check in a distributed, segmented file system, includes: analyzing primary objects of a first segment of the file system to determine if a first primary object points to a second primary object of a second segment separate from the first segment, storing, if the first primary object points to the second primary object of the second segment, a first indication indicating that the first primary object points to the second primary object of the second segment, the first indication indicating an expected location of the second primary object; analyzing a shadow directory of the selected segment to determine an expected location of a third primary object, and an expected pointer of the third primary object indicative of a location and a name of a fourth primary object, the third primary object being contained in a segment other than the first segment; and storing a second indication indicating the expected location of the third primary object and the expected pointe

Abstract: Techniques are provided for producing a shadow directory structure for files or directories owned by servers whose parent directories are owned by different servers in a single distributed file system. For each file or directory whose parent directory resides on a remote server, the server owning the file or directory produces a shadow directory structure. The shadow structure may be used in a variety of ways, e.g., to access an orphan when the server owning the orphan's parent directory is offline (e.g., down, failed, or otherwise inaccessible), or to perform a partial file system consistency check (a partial fsck) to verify consistency of segments of the file system.

Abstract: An arrangement is disclosed for use in connection with a host computer connected to a mass storage subsystem, the mass storage subsystem storing information for use in connection with processing of at least one program by the host computer. The arrangement comprises a program input/output interface, a mass storage subsystem interface and a file system control. The program input/output interface is configured to receive program input/output read and write requests from a program, each program input/output read and write request initiating an input/output operation in connection with information stored on a mass storage subsystem. The mass storage subsystem interface is configured to facilitate communications with the mass storage subsystem, including transferring a storage subsystem input/output read and write request thereto and receiving information therefrom.

Abstract: File locks and file metadata are distributed from a file manager to clients in a data network to permit the clients to share access to file data in data storage. The file manager is permitted to grant a second lock upon the file data without necessarily receiving notification from a client that it has relinquished a first lock on the file data while ensuring that conflicting locks are never granted. The client sets the beginning of a first period of time over which the client may access the file data once the first lock on the file data has been granted by the file manager, and the client sends a lock request to the file manager. The file manager responds by setting the beginning of a second period of time such that the first period of time is certain to have expired once the second period of time has expired, granting the first lock upon the file data to the client, and transmitting a lock grant message to the client.