Administrator's Guide

Glossary
Booted system
environment
The system environment that is currently running — also known as the current, active, or running
system environment.
CLI Command line user interface
Clone * (noun) - clone - a Cloned System Image . * (verb) - clone - to create a Cloned System Image.
Cloned system
image
A copy of the booted volume group from the system image of a booted system environment —
produced by the drd clone command. A cloned system image may be inactive, or the cloned
system image may be booted, in which case the system activities are started and the clone
becomes the system image in the booted system environment. When a particular system image
is booted, all other system images are inactive. A system administrator may modify a cloned
system image by installing software on it using the drd runcmd command.
DRD Dynamic Root Disk. The collection of utilities that manages creation, modification, and booting
of system images.
DRD-chrooted shell The modification environment provided by the DRD utilities for managing (swinstalling, swremoving,
and swverifying) software to and from an inactive system image while logged on to a booted
system environment. Because the POSIX shell is running in an environment provided by the chroot
command, modifications to the booted system environment's files are prevented. In addition, the
file systems of the inactive system image, mounted under the chroot directory, are available
for software management on the inactive system image.
DRD-safe Refers to software packages for HP-UX, as well as to HP-UX commands. A package is DRD-safe
if it can be swinstalled, swremoved, and swverified on an inactive system image without modifying
any part of the booted system environment. There is no requirement that the package can be
configured on an inactive system image. Examples of components of the booted system environment
that cannot be changed are: the installed software, file systems, device configuration, process
space, kernel definition, networking configuration, users and passwords, and auditing and
security. A command is DRD-safe if it can be run in a DRD runcmd environment without modifying
any part of the booted system environment. Further information on DRD-safe is available in the
Dynamic Root Disk: Quick Start & Best Practices white paper, which is available at http://
www.hp.com/go/drd-docs.
Hot backup See Hot recovery
Hot maintenance The ability to perform modifications to an inactive system image using commands issued on the
booted system environment without affecting the booted system environment.
Hot recovery The ability to return to a known good system environment simply by booting. That is, have a
backup system image standing by waiting to be used. Sometimes referred to as hot backup.
LVM Logical Volume Manager. A subsystem that manages disk space — supplied at no charge with
HP-UX.
Original system
environment
A booted system environment whose system image is cloned to create another system image.
Each system image has exactly one original system environment. (That is, the booted system
environment at the time the drd clone command was issued.)
Rehost The capability to boot a DRD clone of an LVM-managed Itanium-based copy of HP-UX 11i v3 on
a system other than the one where it was created. DRD provides the drd rehost command
that copies the system information file—containing hostname, IP address, and other system-specific
information—to EFI/HPUX/SYSINFO.TXT on the disk to be rehosted.
Root file system The file system that must be mounted at /.
System activities All of the running processes that correspond to programs on a booted system. This includes the
running kernel, all network processes, all daemons and all other processes — both system and
user. System activities frequently access in-memory copies of data. Thus any change to in-memory
data may affect system activities.
System
environment
The combination of the system image and the system activities that comprise a running installation
of HP-UX.
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