System and method for efficient backup using hashes
US8484427B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2011 |
| Grant date | Jul 9, 2013 |
| Priority date | — |
| Expiry date | Oct 20, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1451
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
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 contains indicators for the links that define if a block contains the content or if the block points to another block, (k) also indicators that reflect used and unused blocks such t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.