System and method for backing up computer files over a wide area computer network
US6014676A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1998 |
| Grant date | Jan 11, 2000 |
| Priority date | — |
| Expiry date | May 16, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99955
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system backs up computer files to a remote site via modem. Files of a user computer that are found in a common library at the remote site initially are not copied to the remote site, whereas files not in the library are copied to the remote site. Then, periodically the user computer determines which blocks have been changed, and the user computer transmits only changed blocks to the remote site. The blocks are gathered in "chunk" files, and when a chunk file reaches a predetermined size, it is transmitted to the remote site for updating the back up version of the respective file. The process then resumes identifying changed blocks. In addition to flagging the changed block for transfer, the process resynchronizes the local data file with the backed up version using a two-step comparison, first comparing the first two characters in the block with a pre-stored character set, and then, if the first comparison results in a match, comparing a digital signature of the changed block with a pre-stored signature. If either comparison results in a mismatch, the test is repeated using, as the first byte of the test block, the next byte in the sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.