A method of validating metadata pages that map to user data in a data storage system is provided. The method includes (a) obtaining first information stored for a first metadata page and second information stored for a second metadata page, the first and second metadata pages having a relationship to each other within a hierarchy of metadata pages for accessing user data; (b) performing a consistency check between the first information and the second information, the consistency check producing a first result in response to the relationship being verified and a second result otherwise; and (c) in response to the consistency check yielding the second result, performing a corrective action to restore consistency between the first and second information. An apparatus, system, and computer program product for performing a similar method are also provided.

A method, an electronic device, and a computer program product for managing a file system are provided. For example, the method comprises causing multiple data blocks to be written to a storage space of the file system, the size of each of the multiple data blocks being not lower than a threshold size, and creating at least one space fragment in the storage space, the size of each of the at least one space fragment not exceeding the threshold size. Therefore, this solution can quickly and efficiently age a file system.

Examples may include storage of a small object representation in a deduplication system. Examples may store the small object representation of an object in the deduplication system based on a determination that the object is smaller than a threshold size. In examples, the small object representation may include a direct reference from a top-level data structure to small object metadata in a bottom-level data structure of the small object representation.

A method includes receiving, at a container registry, a container image including a set of files, determining that at least one file of the set of files is a duplicate of a previously stored container image file at the container registry. The method further includes storing the container image at the container registry with the at least one file of the plurality of files that is a duplicate of the previously stored container image file removed from the container image.

In general, embodiments of the invention relate to storing data and managing the stored data in linked nodes. More specifically, embodiments of the invention relate to nodes linked together in a daisy chain configuration such as, but not limited to, a single-chain configuration and a dual-chain configuration, which use data protection domain (DPD) information to determine where and/or how to store the data.

Disclosed are techniques for defragmentation in deduplication storage systems. Machine language determines using deduplication metadata that at least some of an incoming input/output stream is a duplicate of at least part of a source volume whose physical locations of its stored data are fragmented in backend storage. Subsequently, defragmentation is carried out on the stored data by using the incoming input/output stream to write the data into sequential chunks at new physical locations in the backend storage and updating the source volume location mappings to the new physical locations.

One example method includes optimizing client-side deduplication. When backing up a client, an overwrite ratio is determined based on a size of actual changes made to a volume and a size indicated by changes in a change log. Client-side deduplication is enabled or disabled based on a value of the overwrite ratio.

A system and method for managing tables in a storage system is described.

In some embodiments, a method receives data for a block in a blockchain during a recovery process in which a recovering replica is recovering the block for a first instance of the blockchain being maintained by the recovering replica. The block is received from a second instance of the blockchain being maintained by a source replica. The method splits the data for the block into a plurality of chunks. Each chunk includes a portion of the data for the block; It is determined whether the recovering replica can recover a chunk in the plurality of chunks using a representation of the chunk. In response to determining that the recovering replica can recover the chunk, sending the representation of the chunk to the recovering replica. In response to determining that the recovering replica cannot recover the chunk, sending the data for the chunk to the recovering replica.

The disclosed embodiments disclose techniques that facilitate of avoiding client timeouts in a distributed filesystem. Multiple cloud controllers collectively manage distributed filesystem data that is stored in one or more cloud storage systems; the cloud controllers ensure data consistency for the stored data, and each cloud controller caches portions of the distributed filesystem in a local storage pool. During operation, a cloud controller receives from a client system a request for a data block in a target file that is stored in the distributed filesystem. Although the cloud controller is already caching the requested data block, the cloud controller delays transmission of the cached data block; this additional delay gives the cloud controller more time to access uncached data blocks for the target file from a cloud storage system, thereby ensuring that subsequent requests of such data blocks do not exceed a timeout interval on the client system.