Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

514 Glossary
sector
A unit of size, which can vary between systems. Sector size is set per device (hard drive, CD-ROM,
and so on). Although all devices within a system are usually configured to the same sector size for
interoperability, this is not always the case. A sector is commonly 1024 bytes.
shared disk group
A disk group in which access to the disks is shared by multiple hosts (also referred to as a cluster-
shareable disk group). Also see private disk group.
shared volume
A volume that belongs to a shared disk group and is open on more than one node of a cluster at the
same time.
shared VM disk
A VM disk that belongs to a shared disk group in a cluster.
slave node
A node that is not designated as the master node of a cluster.
slice
The standard division of a logical disk device. The terms partition and slice are sometimes used
synonymously.
snapshot
A point-in-time copy of a volume (volume snapshot) or a file system (file system snapshot).
spanning
A layout technique that permits a volume (and its file system or database) that is too large to fit on a
single disk to be configured across multiple physical disks.
sparse plex
A plex that is not as long as the volume or that has holes (regions of the plex that do not have a
backing subdisk).
Storage Area Network (SAN)
A networking paradigm that provides easily reconfigurable connectivity between any subset of
computers, disk storage and interconnecting hardware such as switches, hubs and bridges.
stripe
A set of stripe units that occupy the same positions across a series of columns.
stripe size
The sum of the stripe unit sizes comprising a single stripe across all columns being striped.
stripe unit
Equally-sized areas that are allocated alternately on the subdisks (within columns) of each striped
plex. In an array, this is a set of logically contiguous blocks that exist on each disk before allocations
are made from the next disk in the array. A stripe unit may also be referred to as a stripe element.
stripe unit size
The size of each stripe unit. The default stripe unit size is 64KB. The stripe unit size is sometimes also
referred to as the stripe width.
striping