Abstract: A method, system and computer program product for backup and restoration of data. Hash values for data blocks subject to backup are generated. After a number of hashes are accumulated, e.g., on a backup server, these hashes are sorted. Then, the hashes are compared against the hash values in the hash table corresponding to data blocks that have already been backed up. If a hash matches the hash from the hash table, a pointer to the block in the archive is written to the table of pointers to the redundant blocks. Then, this hash value is deleted from a set of the hash values. A check is made if a hash is the last in the group. If the hash is the last in the group, the remaining unique hash values are written into the hash table. Otherwise, the next hash is selected from the group. The redundant data blocks are discarded and only unique data is backed up.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for efficient backup using hashes One of the methods includes forming an image of a storage device, wherein contents of blocks of the storage device are restorable from the contents of blocks of the image. The method includes generating a first plurality of hash values, each hash value generated from contents of a block of the image. The method includes selecting a block of the storage device. The method includes generating a hash value from the contents of the selected block. The method includes determining whether the hash value occurs in the plurality of hash values. The method also includes generating an entry in the image in response to the determination.

Abstract: A method for data backup including (a) forming an image of the storage device; (b) for each block to be backed up to the image, generating a hash; (c) for each block stored in the image, storing a hash in a hash table; (c) for each additional block of the storage device to be backed up, generating a hash; (d) sorting all the generated hashes and deleting duplicate hashes; (e) comparing the hashes to identify candidate blocks that might have identical contents with contents of blocks stored in the image; (f) if the hashes are not coincident, then backing up, to the image, contents of unidentified blocks and blocks that do not have identical hashes, and (g) otherwise, storing links in the image instead of the contents of the blocks, (h) after checking all the hashes for those blocks that need to be backed up, writing only unique hashes to the hash table; (h) links for multiple blocks with identical contents point to a single block in the image, (i) the image contains a bitmap of the backup; (j) the bitmap conta

Abstract: A system for consolidation of backups. Each backup includes data and a map with offsets or addresses that point to data of current and/or previous backups. Backup are selected for consolidation. The offsets in the maps of the selected backups are combined into a single set of offsets; consolidating the selected backups to a new backup that contains the latest data from the selected backups, determined based on the offsets in the single set. The offsets in the single set are updated to point to the data in the new backup. The updated offsets are stored in the new backup as part of a backup map of the new backup. The selected backups comprise one initial full backup and at least one backup. Offsets from the maps of first backup of the selected sequence of backups up to the last created backup are checked.

Abstract: A system and method for multivolume file system backup without suspending activity of user application programs uses a file system snapshot of two and more partitions or volumes of the storage device, or two and more data storages, significantly increasing computer system availability and allows backing up two and more partitions of the storage device without interrupting computer services. Backup procedure is performed online, simultaneously creates snapshots of two and more partitions of the storage device or storage devices in the pre-selected point of time and copies data blocks from partitions into the backup storage device, optionally through the intermediate storage device.

Abstract: A system, method and computer program product for consolidation of backups, wherein each backup includes data and a backup map with offsets that point to data of current and/or previous backups, including selecting a plurality of backups to be consolidated; combining the offsets in the backup maps of the selected backups into a single set of offsets; consolidating the selected backups to a new backup that contains the latest data from the selected backups, the latest data determined based on the offsets in the single set; updating the offsets in the single set to point to the data in the new backup; and storing the updated offsets in the new backup as part of a backup map of the new backup. The selected backups comprise one initial full backup and at least one backup. In the combining step, the addresses from the backup maps of first backup of the selected sequence of backups up to the last created backup is checked. The selected backups are organized into a tree.

Abstract: A system, method and computer program product for consolidation of incremental backups, wherein each incremental backup includes data and a backup map with links that point to data of current and/or previous backups, including selecting a plurality of incremental backups to be consolidated; combining the links in the backup maps of the selected backups into a single set of links; consolidating the selected backups to a new backup that contains the latest data from the selected backups, the latest data determined based on the links in the single set; updating the links in the single set to point to the data in the new backup; and storing the updated links in the new backup as part of a backup map of the new backup. The selected backups comprise one initial full backup and at least one incremental backup. In the combining step, the addresses from the backup maps of first backup of the selected sequence of backups up to the last created backup is checked.

Abstract: A method, system computer program product recorded on a computer readable medium, for fast incremental backup of a storage device includes selecting an area of the data storage device for backup; creating the bitmap of data storage device; reading the selected area of the data storage device; converting data read from the data storage device into a usable format for the comparison of descriptors; reading descriptors of logical storage units of the selected area; discarding selected data access attributes of the descriptors; generating hash values for the descriptors; comparing the hash values of the descriptors of the logical storage units of the selected area with the hash values of the descriptors of previously archived logical storage units; for physical storage units related to logical storage units of the selected area whose hash values of the descriptors are identical to the hash values of the descriptors of the archived logical storage units, checking if these physical storage units need to be backed u

Abstract: A method of incremental backup of a storage device includes reading descriptors of logical storage units of the storage device; comparing the descriptors of the logical storage units of the storage device with descriptors of archived logical storage units; for logical storage units of the storage device whose descriptors are not identical to the descriptors of the archived logical storage units, backing up contents of physical storage units that correspond to those logical storage units of the storage device; and, for logical storage units of the storage device whose descriptors are identical, performing a comparison step to check if these logical storage units need to be backed up. The logical storage units can be files. The comparison step can be, e.g., (1) bit-wise comparison of the logical blocks, (2) comparing control sums of the logical blocks, and (3) comparing log files relating to the logical storage units The physical storage units can be blocks. The descriptors can be, e.g.