Veritas Volume Manager 5.0.1 Migration Guide, HP-UX 11i v3, First Edition, November 2009

block A unit of space for data on a disk, typically having a size of 1024-bytes.
Dirty Region Logging Dirty Region Logging (DRL) is an optional property of a volume, used to provide
a speedy recovery of mirrored volumes after a system failure. DRL keeps track of
the regions that have changed due to I/O writes to a mirrored volume.
file system The organization of files on storage devices. The term file system can refer either
to the entire file system or to a subsection of that file system, contained within a
disk section or a logical volume that can be mounted or unmounted from that
tree.
logical volume A logical structure that is a map of storage areas on physical volumes. A logical
volume can be conceptualized as a storage device of flexible size. The data in a
logical volume can be mapped to one or more physical volumes. A virtual disk
device that represents a contiguous virtual disk space that maps to single or
multiple areas on a single or multiple physical volumes.
LVM The Logical Volume Manager (LVM) is a subsystem for managing disk space. LVM
is an HP-UX product, similar to VxVM.
LIF The Logical Interchange Format (LIF) is a HP mass-storage format that can be
used for interchange of files among various HP computer systems. Each boot disk
has a LIF directory that contains boot programs.
logical Extent A set of logical blocks that maps to one physical extent and is a basic unit of access
in a logical volume.
LVMREC The LVM record, which is an identifier that is set on each disk when it is initialized
the first time by LVM. There are two copies of the LVMREC; one is at sector 8,
while the other is at sector 72.
mirror disk/UX HP-UX software product that allows disk mirroring as part of LVM functionality.
Mirror Disk/UX allows up 2 mirror copies in a volume.
Mirror Write Cache
(MWC)
A MirrorDisk/UX mechanism whose use is optional, that tracks outstanding mirror
write requests and provides a basis for the resynchronization of data blocks after
a system crash or power failure.
physical volume A disk that has been initialized by LVM becomes known as a physical volume.
public region A region of a physical disk managed by VxVM that contains available space and
is used for allocating subdisks.
Glossary