Data storage library array with log-structured file system which allows simultaneous write and garbage collection
US5530850A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1993 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Oct 25, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99957
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data storage library system, preferably arranged in an array of independent libraries, uses a log-structured file (LSF) data architecture and assigned roles for the individual storage devices in the library. Each library includes a plurality of storage devices, such as optical disk drives, and a store of removable media units, such as optical disks, that are mounted and dismounted from the storage devices. The log-structured library is similar to fixed media systems having LSF data architectures in that it employs a directory to map the local address of a data set to its physical storage location, but is different in that it divides the jobs of reading and writing (log accesses) and garbage collection among the different storage devices of the library. As required, the dismountable media units are moved from the storage area and mounted on a device assigned the appropriate role. The roles assigned to the storage devices are flexible and can change as needed. The system allows both log accesses and garbage collection to occur simultaneously. The garbage collection process segregates the data into "hot" and "cold" segments, according to the age of the data. This allows all the cold…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.