Flexible-capacity scaling for efficient access of ordered data stored on magnetic tape media
US5757571A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Mar 12, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/95
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Various data storage formats help to efficiently locate, read, and write user data stored on magnetic tape media. A tape is formatted by writing multiple segment-headers, free from any interleaved access of user data. Adjacent segment-headers are spaced by a predetermined interval to define multiple data storage segments. Segment-headers all contain a unique key, which is copied into a key index to identify valid segments. After formatting, normal tape accesses can be performed. Without erasing any old headers or data, a new formatting scheme can be established by writing new segment-headers on the tape. The new segment-headers include a new unique key, replacing the previous key in the key index. Previous segment-headers stored on the tape are ignored, since they lack the updated key. Segments may be selectively grouped to provide independently addressable partitions. Mapping between segments and partitions can use a fixed relationship (e.g. one-to-one), or each partition may be variably sized according to the amount of data to be stored therein. Variable-sized partitions may be automatically padded with a selected number of empty segments. Another feature is flexible-capacity sca…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.