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

515Glossary
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.
swap area
A disk region used to hold copies of memory pages swapped out by the system pager process.
swap volume
A VxVM volume that is configured for use as a swap area.
transaction
A set of configuration changes that succeed or fail as a group, rather than individually. Transactions
are used internally to maintain consistent configurations.
volboot file
A small file that is used to locate copies of the boot disk group configuration. The file may list disks
that contain configuration copies in standard locations, and can also contain direct pointers to
configuration copy locations. The volboot file is stored in a system-dependent location.
VM disk
A disk that is both under VxVM control and assigned to a disk group. VM disks are sometimes
referred to as VxVM disks or simply disks.
volume
A virtual disk, representing an addressable range of disk blocks used by applications such as file
systems or databases. A volume is a collection of from one to 32 plexes.
volume configuration device
The volume configuration device (/dev/vx/config) is the interface through which all
configuration changes to the volume device driver are performed.
volume device driver
The driver that forms the virtual disk drive between the application and the physical device driver
level. The volume device driver is accessed through a virtual disk device node whose character device
nodes appear in
/dev/vx/rdsk, and whose block device nodes appear in /dev/vx/dsk.
volume event log
The device interface (/dev/vx/event) through which volume driver events are reported to
utilities.
vxconfigd
The VxVM configuration daemon, which is responsible for making changes to the VxVM
configuration. This daemon must be running before VxVM operations can be performed.