AMASS Overview
storage policy
DataMgr migrates files using storage policies, including Single Copy,
striping
The UNIX operating system allows AMASS to cache data across multiple magnetic disks on the server or across partitions on a single magnetic disk on the server. This feature improves AMASS throughput. AMASS divides the data into segments (stripes) and writes each segment either to multiple disks or to partitions on a disk. These raw disks or raw partitions are defined as cache space names with the AMASS installation script. See also cache.
stub file
DataMgr leaves a stub file on a file system after the original file has been migrated to AMASS. The original file is truncated (stubbed) to the smallest allocatable disk block on the file system and its contents is replaced with all the information necessary to access the migrated file.
T
TCP/IP
Transmission Control Protocol/Internet Protocol. Runs on top of Ethernet to provide
thrashing
Unnecessary movement of the library’s robotics. For example, retrieving disc 1, then disc 6, then 1, then 6. Thrashing causes access delays and premature hardware failure.
truncate
Remove the file data blocks from disk, leaving the inodes on disk. Only files that remain unchanged since the last storage to media can have their data blocks truncated from disk. A
U
UNIX™
A computer operating system that runs on workstations, servers, mainframes, and supercomputers.
Glossary |