Veritas Storage Foundation™ for Oracle 5.0.1 Administrator's Guide

internally defined unique ID. The root disk group (rootdg) is a special private disk
group
disk name A Veritas Volume Manager logical or administrative name chosen for the disk,
such as disk03. The term disk media name is also used to refer to the disk name.
DMP See “Dynamic Multipathing.”
DSS See “Decision Support Systems.”
Dynamic Multipathing Dynamic Multipathing (DMP) is a Veritas Volume Manager feature that allows
the use of multiple paths to the same storage device for load balancing and
redundancy.
error handling Routines in a program that respond to errors. The measurement of quality in
error handling is based on how the system informs the user of such conditions
and what alternatives it provides for dealing with them.
evacuate Moving subdisks from the source disks to target disks.
exabyte A measure of memory or storage. An exabyte is approximately
1,000,000,000,000,000,000 bytes (technically 2 to the 60th power, or
1,152,921,504,606,846,976 bytes). Also EB.
extent A logical database attribute that defines a group of contiguous file system data
blocks that are treated as a unit. An extent is defined by a starting block and a
length.
extent attributes The extent allocation policies associated with a file and/or file system. For example,
see “address-length pair.”
failover The act of moving a service from a failure state back to a running/available state.
Services are generally applications running on machines and failover is the process
of restarting these applications on a second system when the first has suffered a
failure.
file system A collection of files organized together into a structure. File systems are based
on a hierarchical structure consisting of directories and files.
file system block The fundamental minimum size of allocation in a file system.
fileset A collection of files within a file system.
fixed extent size An extent attribute associated with overriding the default allocation policy of the
file system.
fragmentation Storage of data in non-contiguous areas on disk. As files are updated, new data is
stored in available free space, which may not be contiguous. Fragmented files
cause extra read/write head movement, slowing disk accesses.
free space An area of a disk under Veritas Volume Manager control that is not allocated to
any subdisk or reserved for use by any other VxVM object.
Glossary404