VERITAS File System 4.1 Administrator's Guide

Glossary
metadata
Glossary262
M
metadata Structural data describing the
attributes of files on a disk.
MB Megabyte (220 bytes or 1024 kilobytes).
mirror A duplicate copy of a volume and the
data therein (in the form of an ordered
collection of subdisks). Each mirror is one
copy of the volume with which the mirror is
associated.
multi-volume file system A single file
system that has been created over multiple
volumes, with each volume having its own
properties.
MVS Multi-volume support.
N
node One of the hosts in a cluster.
node abort A situation where a node leaves
a cluster (on an emergency basis) without
attempting to stop ongoing operations.
node join The process through which a
node joins a cluster and gains access to
shared disks.
O
object location table (OLT) The
information needed to locate important file
system structural elements. The OLT is
written to a fixed location on the underlying
media (or disk).
object location table replica A copy of the
OLT in case of data corruption. The OLT
replica is written to a fixed location on the
underlying media (or disk).
P
page file A fixed-size block of virtual
address space that can be mapped onto any
of the physical addresses available on a
system.
preallocation A method of allowing an
application to guarantee that a specified
amount of space is available for a file, even if
the file system is otherwise out of space.
primary fileset The files that are visible
and accessible to the user.
Q
Quick I/O file A regular VxFS file that is
accessed using the ::cdev:vxfs: extension.
Quick I/O for Databases Quick I/O is a
VERITAS File System feature that improves
database performance by minimizing
read/write locking and eliminating double
buffering of data. This allows online
transactions to be processed at speeds
equivalent to that of using raw disk devices,
while keeping the administrative benefits of
file systems.
quotas Quota limits on system resources for
individual users for file and data block usage
on a file system. See also hard limit and
soft limit..