Abstract: A composite layout including a plurality of ranked sub-layouts may be used to provide various functionality for data object look-up and file system activities. Each sub-layout may include mapping information linking one or more extents of a data object to one or more locations on one or more storage apparatuses. Generally, mapping information in the highest priority sub-layout including mapped extents may be used during “reads” while the highest priority sub-layout may be used for “writes.

Abstract: A system utilizing elastic spares includes nodes and devices to store one or more data objects having information. The data object includes data object units each assigned to a storage location on a different node than the other units. The data object includes one or more spare units to store reconstructed information of a failed unit. When one of the data objects has a failed unit and no spare units available to store reconstructed information, a controller of the system assigns an elastic spare unit to an available storage location of one of the nodes. Reconstructed information of the failed unit is stored in the elastic spare unit.

Abstract: A method of replicating a source file system on a storage system, the method including: utilising a changelog operable to store sequentially a data record corresponding to a modification of a source file system by a storage request; specifying a first data record of the changelog at a first time; initiating a scan of the directory inodes of the source file system at the first time; scanning the directory inodes; completing the scan at a second time later than the first time; specifying a second data record of the changelog at the second time; storing, in a database, information corresponding to the scanned directory inodes; updating the database with sequential data records from the first data record to the second data record of the changelog; and building, on a computer system, a replica target file system based on the database.

Abstract: A node includes a controller that includes one or more processors. The controller may be configured to load data from a storage data block of a plurality of storage data blocks stored on one or more first data storage devices to a working data block stored on one or more second data storage devices. In response to a node experiencing a failure, the controller can be configured to determine a change value for the working data block. The controller can be configured to determine whether data stored in the working data block is different than data stored in the corresponding storage data block based on the determined change value and a provided change value that corresponds to the storage data block.

Abstract: A node includes a controller that includes one or more processors. The controller may be configured to load data from a storage data block of a plurality of storage data blocks stored on one or more first data storage devices to a working data block stored on one or more second data storage devices. In response to a node experiencing a failure, the controller can be configured to determine a change value for the working data block. The controller can be configured to determine whether data stored in the working data block is different than data stored in the corresponding storage data block based on the determined change value and a provided change value that corresponds to the storage data block.

Abstract: A system utilizing elastic spares includes nodes and devices to store one or more data objects having information. The data object includes data object units each assigned to a storage location on a different node than the other units. The data object includes one or more spare units to store reconstructed information of a failed unit. When one of the data objects has a failed unit and no spare units available to store reconstructed information, a controller of the system assigns an elastic spare unit to an available storage location of one of the nodes. Reconstructed information of the failed unit is stored in the elastic spare unit.

Abstract: A composite layout including a plurality of ranked sub-layouts may be used to provide various functionality for data object look-up and file system activities. Each sub-layout may include mapping information linking one or more extents of a data object to one or more locations on one or more storage apparatuses. Generally, mapping information in the highest priority sub-layout including mapped extents may be used during “reads” while the highest priority sub-layout may be used for “writes.

Abstract: In distributed state systems, server nodes can receive operation requests from multiple clients. When a server node executes an operation request, the server node can store an indicator of the operation request to a log of operations and send a reply message to the requesting client. The reply message can include a reply log having a list of N executed operation requests. If the server needs rebuilding, any operations not already stored to the server node log may be lost. The server can rebuild lost operations of a file system by receiving the reply logs or indicators of the operations therein from one or more clients.

Abstract: A method of writing data to a distributed file system including a file system client, a server and a storage resource target, includes generating, on the client, a write request including a byte stream to be written to the storage resource target; formatting, on the client, the byte stream into sectors in accordance with the T10 protocol, the sectors including a data field and a protection information field, the protection information field including a guard field, an application field and a reference field; computing, on the client, checksum data for the guard field; sending, across a network, the data and the protection information to the server; verifying, in T10-capable hardware on the server, the checksum data for the guard field; verifying, on the storage resource target, the checksum data for the guard field; and storing the data on the storage resource target.

Abstract: A method of replicating a source file system on a storage system, the method including: utilising a changelog operable to store sequentially a data record corresponding to a modification of a source file system by a storage request; specifying a first data record of the changelog at a first time; initiating a scan of the directory inodes of the source file system at the first time; scanning the directory inodes; completing the scan at a second time later than the first time; specifying a second data record of the changelog at the second time; storing, in a database, information corresponding to the scanned directory inodes; updating the database with sequential data records from the first data record to the second data record of the changelog; and building, on a computer system, a replica target file system based on the database.

Abstract: A method of writing data to a distributed file system including a file system client, a server and a storage resource target, includes generating, on the client, a write request including a byte stream to be written to the storage resource target; formatting, on the client, the byte stream into sectors in accordance with the T10 protocol, the sectors including a data field and a protection information field, the protection information field including a guard field, an application field and a reference field; computing, on the client, checksum data for the guard field; sending, across a network, the data and the protection information to the server; verifying, in T10-capable hardware on the server, the checksum data for the guard field; verifying, on the storage resource target, the checksum data for the guard field; and storing the data on the storage resource target.

Abstract: There is provided a method of writing data to a data sector of a storage device. The data sector has at least one parity sector associated therewith, each sector being configured to include a data field and a data integrity field. The data integrity field including a guard field, an application field and a reference field. The method includes providing data to be written to an intended sector; generating, for the intended sector, version information for the sector; generating a version vector based on the version information for the data sector; and writing the data to the data field of the data sector; writing the version information to the application field of the data sector; and writing the version vector to the application field of the parity sector.

Abstract: A system and method are provided for the expedited reprinting of documents at a printer. The method comprises: receiving an initial print job identified with a job identification (JID); rendering the print job into a bitmap; in response to rendering the bitmap, initially printing a document; saving the bitmap in memory; and, in a job table, creating a cross-reference between the JID and the saved bitmap. Subsequently, the method comprises: receiving a selected JID; accessing the job table; accessing a print engine-ready bitmap associated with the JID by using the job table to locate a bitmap cross-referenced to the received JID; reading the located bitmap from a printer memory; and, reprinting a document in response to the bitmap. An associated network server can be used for posting a job table with selectable JIDs on an HTML webpage. Alternately, the JID selection is received in a print driver communication.

Abstract: Embodiments of the present invention comprise methods and systems for associating a hard-copy document with computer-readable information and for accessing that information.