The embodiments set forth a technique for managing file nodes within a storage device. According to some embodiments, the method can include the steps of (1) receiving a transaction request that involves modifying a plurality of file nodes, (2) analyzing the plurality of file nodes against temporal transaction information to identify, among the plurality of file nodes, at least one group of file nodes that were previously modified in conjunction with at least one previously-executed transaction request, (3) modifying each file node in the at least one group of file nodes in accordance with the transaction request to establish a modified group of file nodes, (4) allocating, within the storage device, physical storage space for storing the modified group of file nodes, and (5) contiguously writing the modified group of file nodes into the allocated physical storage space.

Apparatus and method for configuring a data storage device as a write once read many (WORM) drive. In some embodiments, the storage device has a rotatable disc with at least one data recording layer, and a data transducer that is selectively moveable with respect to the rotatable disc. The data transducer has a write element configured to write data to the data recording layer, and a read element configured to read data from the data recording layer. A control circuit is configured to physically disable the write element in response to a write element disable signal. The disabling of the write element prevents further writing of data to the data recording layer. The read element remains operative to continue reading data from the data recording layer after the write element has been disabled.

The disclosed computer-implemented method for write-once-read-many storage may include (1) receiving, at a file system on the computing device, a request to assign a write-once-read-many (WORM) attribute to a file, wherein the request is received from an application, (2) setting, in response to the request to assign the WORM attribute to the file, a WORM flag in an extended attribute associated with the file, and (3) associating with the file, in response to the setting of the WORM flag, a retention period attribute and read-only access until the end of the retention period. The provided systems and methods may provide per-file WORM support at a file system level using extended attributes of the file system. Various other methods, systems, and computer-readable media are also disclosed.

In some examples, one or more computing devices may perform deduplication of data. For instance, a first device may receive, from a second device, a first data-portion identifier corresponding to a first deduplication data portion. The first device may include a first index portion of a deduplication index and the second device may include a second index portion of the deduplication index. Further, the first data-portion identifier may be received based on a first data-portion identifier portion being in a range of values assigned to the first index portion. The first device may locate, in the first index portion of the deduplication index, a second data-portion identifier that matches the first data-portion identifier. The first device may associate the first reference information for the first deduplication data portion with a second deduplication data portion referenced by reference information associated with the second data-portion identifier.

Apparatus and method for configuring a data storage device as a write once read many (WORM) drive. In some embodiments, the storage device has a rotatable disc with at least one data recording layer, and a data transducer that is selectively moveable with respect to the rotatable disc. The data transducer has a write element configured to write data to the data recording layer, and a read element configured to read data from the data recording layer. A control circuit is configured to physically disable the write element in response to a write element disable signal. The disabling of the write element prevents further writing of data to the data recording layer. The read element remains operative to continue reading data from the data recording layer after the write element has been disabled.

A data management system may support techniques for immutable storage of snapshot data entities, which may each include data corresponding to one or more snapshots, in a cloud environment. The data management system may determine respective retention periods and respective immutability periods for the snapshot data entities. The data management system may extend the respective immutability period for a first snapshot data entity based on the respective retention period for the first snapshot data entity being greater than or equal to a threshold duration. Additionally or alternatively, the data management system may maintain (refrain from extending) the respective immutability period for a second snapshot data entity based at least in part on the respective retention period for the second snapshot data entity being less than the threshold duration.

One or more techniques and/or systems are provided for performing host side deduplication. Host side deduplication may be performed upon writeable data within a write request received at a host computing device configured to access data stored by a storage server. The host side deduplication may be performed at the host computing device to determine whether the writeable data is already stored by the storage server based upon querying a host side cache comprising data stored by a storage server and/or a data structure comprising unique signatures of data stored by the storage server. If the writeable data is stored by the storage server, then a deduplication notification excluding the writeable data may be sent to the storage server, otherwise a write command comprising the writeable data may be sent. Accordingly, unnecessary network traffic of redundant data already stored by the storage server may be reduced.

A data management system may support techniques for immutable storage of snapshot data entities, which may each include data corresponding to one or more snapshots, in a cloud environment. The data management system may determine respective retention periods and respective immutability periods for the snapshot data entities. The data management system may extend the respective immutability period for a first snapshot data entity based on the respective retention period for the first snapshot data entity being greater than or equal to a threshold duration. Additionally or alternatively, the data management system may maintain (refrain from extending) the respective immutability period for a second snapshot data entity based at least in part on the respective retention period for the second snapshot data entity being less than the threshold duration.

Techniques index a file. The techniques involve: determining, based on a first mapping stored in a first inode associated with the file, whether a predetermined conversion condition is satisfied. The first mapping points to a plurality of data blocks of a file system storing the file in a first index structure. The techniques further involve, in response to determining that the predetermined conversion condition is satisfied, creating a second inode associated with the file. The techniques further involve converting the first mapping into a second mapping to be stored in the second inode. The second mapping points to the plurality of data blocks in a second index structure different from the first index structure.

Examples disclosed herein provide systems, methods, and software for avoiding data replication using sparse files. In one example, a method of using a sparse file to manage modifications to read-only files includes identifying an open file request on a computing system for a read-only file, and generating the sparse file corresponding to the read-only file. The method further includes identifying a modification to the read-only file and, responsive to identifying the modification, initiate a write to the sparse file based on the modification and identifying the write in a region map.