Delta compression method, system and computer program product. Portions of source and target data files are hashed using a hashing function. A target data file is compared against the source data file to determine at least one delta difference between the files. A source data file hashing table is generated. The table includes hashed portions of the source and target data files stored in corresponding source file offset locations and corresponding target file offset locations, respectively. Portions of the source and target files are compared using corresponding source and target file offset locations. At least one common sequence of characters in the portions of the source and target files is determined based on the comparison. A patch file is generated based on the determined sequence of characters.

Methods, systems, and computer program products are included for de-duplicating one or more memory pages. A method includes receiving, by a hypervisor, a list of read-only memory page hints from a guest running on a virtual machine. The list of read-only memory page hints specifies a first memory page marked as writeable. The method also includes determining whether the first memory page matches a second memory page. In response to a determination that the first memory page matches the second memory page, the hypervisor may deduplicate the first and second memory pages.

Technologies for computing rolling hashes include a computing device having a first hash table that includes a first plurality of random-valued entries and a second hash table that includes a second plurality of random-valued entries. The computing device retrieves a block of data from a data buffer and generates a hash based on the block of data, a previously generated hash, the first hash table, and the second hash table. The computing device further determines whether the generated hash matches a predefined trigger and records a data boundary in response to a determination that the generated hash matches the trigger.

Method and apparatus for performing in-place compression is provided. The in-place compression system transfers source data from a partition of a memory to a data buffer based on a read address. Compressed data is created by referencing the source data stored in the data buffer. The system writes the compressed data to the memory partition based on a write address. When the write address points at an address location that stores source data that has not been transferred to the data buffer, the system overwrites the compressed data stored in the memory partition with the source data stored in the data buffer.

A method and system for improving tape drive memory storage is provided. The method includes receiving, by a storage tape drive, a data stream for storage. The data stream is passed through a non-volatile memory device (NVS2) of the storage tape drive. The data stream is divided into adjacent variable length data chunks and a chunk list file including similarity identifiers for each of the adjacent variable length data chunks is generated and stored within a (non-volatile memory device) NVS1. Duplicate data including duplicated data with respect to a group of data chunks of the adjacent variable length data chunks is identified and deleted from the NVS2 of the storage tape drive such that the group of data chunks remains within NVS2. The group of data chunks is written to a data storage tape cartridge. Pointers identifying each data chunk and an associated storage position are generated and stored.

Embodiments of the present invention provide a data object processing method and apparatus, which can divide a data object into one or more blocks; calculate a sample compression ratio of each block, aggregate neighboring consecutive blocks with a same sample compression ratio characteristic into one data segment, and obtain the sample compression ratio of each of the data segments; and select, according to a length range to which a length of each of the data segments belongs and a compression ratio range to which the sample compression ratio of each of the data segments belongs, an expected length to divide the data segment into data chunks, where the sample compression ratio of each of the data segments uniquely belongs to one of the compression ratio ranges, and the length of each of the data segments uniquely belongs to one of the length ranges.

A tenant's clear text data in a multi-tenant storage system can be encrypted using the tenant's cryptographic key to produce encrypted yet compressible data (cryptographic data). The cryptographic data can be encrypted using a system cryptographic key that is managed by the multi-tenant storage system and then stored. Use of the system cryptographic key allows for subsequent maintenance activities such as deduplication and compression to be performed on data stored in the multi-tenant storage system without having to access any of the tenants' cryptographic keys.

A non-volatile memory (NVM) apparatus and a data de-duplication method thereof are provided. The NVM apparatus includes a NVM and a controller. The controller performs an error checking and correcting (ECC) method to convert a raw data into an encoded data. The controller performs the data de-duplication method to reduce a number of times that the same encoded data is repeatedly written into the NVM. The controller generates the feature information corresponding to the raw data by reusing the ECC method. When the feature information is found in a feature list, the encoded data corresponding to the raw data will not be written into the NVM. When the feature information is not found in the feature list, the feature information is added into the feature list, and the encoded data corresponding to the raw data is written into the NVM.

The present disclosure relates to a method, an electronic device, and a computer program product for storage management. According to an example, a method for storage management is provided, including: generating a to-be-stored target data stream based on a to-be-stored object, wherein the target data stream includes at least a part of the object, determining whether the target data stream matches at least one stored data stream that has been stored in a storage apparatus, wherein sizes of the target data stream and the at least one stored data stream depend on their respective content, and, if the target data stream does not match the at least one stored data stream, storing the target data stream in the storage apparatus. Therefore, the performance of storage management can be improved, and the storage costs can be reduced.

A system configured to generate a set of compression dictionary snapshots. The system can determine a subset of a set of compression dictionary definitions, the subset having a first subset comprising one or more definitions that have changed since a time of a previous snapshot and a second subset having one or more definitions associated with a predetermined portion of the dictionary. The system can further generate and store snapshots based at least in part on the determined subset of one or more definitions and determine a plurality of active snapshots from the set of snapshots such that the set of one or more definitions is included in the plurality of active snapshots.