Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

RAID 5, the stripe unit size is 32 sectors (16K). A stripe unit size has also
historically been referred to as a stripe width.
striping A layout technique that spreads data across several physical disks using stripes.
The data is allocated alternately to the stripes within the subdisks of each plex.
subdisk A consecutive set of contiguous disk blocks that form a logical disk segment.
Subdisks can be associated with plexes to form volumes.
superuser A user with unlimited access privileges who can perform any and all operations
on a computer. In UNIX, this user may also be referred to as the “root” user. On
Windows/NT, it is the “Administrator.”
tablespace A tablespace is a storage structure (containing tables, indexes, large objects, and
long data) that allows you to assign the location of database and table data directly
onto containers. Tablespaces reside in database partition groups.
terabyte A measure of memory or storage. A terabyte is approximately 1,000,000,000,000
bytes (technically, 2 to the 40th power, or 1,000 GB). Also TB.
throughput A measure of work accomplished in a given amount of time. For file systems, this
typically refers to the number of I/O operations in a given period of time.
unbuffered I/O I/O that bypasses the file system cache for the purpose of increasing I/O
performance (also known as direct I/O).
Veritas Enterprise
Administrator
Application that is required to access graphical user interface (GUI) functionality.
NBU (Veritas
NetBackup)
A product that lets you back up, archive, and restore files, directories, or raw
partitions that reside on your client system.
VVR (Veritas Volume
Replicator)
A feature of Veritas Volume Manager, VVR is a data replication tool designed to
contribute to an effective disaster recovery plan.
Version Checkpoint In a DB2 UDB EEE or ESE Data Partitioning Feature (DPF) environment, a Version
Checkpoint is a set of checkpoints that spans multiple partitions. A Version
Checkpoint contains one Storage Checkpoint per partition. A Storage Checkpoint
is an efficient snapshot technology for creating a point-in-time image of a currently
mounted VxFS file system. A Storage Checkpoint presents a consistent,
point-in-time view of the file system by identifying and maintaining modified file
system blocks.
volume A logical disk device that appears to applications, databases, and file systems as
a physical disk partition. A logical disk can encompass multiple or one to many
physical volumes.
volume layout A variety of layouts that allows you to configure your database to meet
performance and availability requirements. This includes spanning, striping
543Glossary