Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

458 VERITAS Volume Manager Administrator’s Guide
disk
A collection of read/write data blocks that are indexed and can be accessed fairly quickly.
Each disk has a universally unique identifier.
disk access name
An alternative term for a device name.
disk access records
Configuration records used to specify the access path to particular disks. Each disk access
record contains a name, a type, and possibly some type-specific information, which is
used by VxVM in deciding how to access and manipulate the disk that is defined by the
disk access record.
disk array
A collection of disks logically arranged into an object. Arrays tend to provide benefits
such as redundancy or improved performance. Also see disk enclosure and JBOD.
disk array serial number
This is the serial number of the disk array. It is usually printed on the disk array cabinet or
can be obtained by issuing a vendor- specific SCSI command to the disks on the disk array.
This number is used by the DMP subsystem to uniquely identify a disk array.
disk controller
In the multipathing subsystem of VxVM, the controller (host bus adapter or HBA) or disk
array connected to the host, which the Operating System represents as the parent node of
a disk.
disk enclosure
An intelligent disk array that usually has a backplane with a built-in Fibre Channel loop,
and which permits hot-swapping of disks.
disk group
A collection of disks that share a common configuration. A disk group configuration is a
set of records containing detailed information on existing VxVM objects (such as disk and
volume attributes) and their relationships. Each disk group has an administrator-assigned
name and an internally defined unique ID. The disk group names bootdg (an alias for the
boot disk group), defaultdg (an alias for the default disk group) and nodg (represents
no disk group) are reserved.