HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes (September 2007)

Logical Volume Manager and MirrorDisk/UX Release Notes
About this Document
This document provides information about the Logical Volume Manager (LVM) and
MirrorDisk/UX products in the September 2007 release of HP-UX 11i v3.
LVM and MirrorDisk/UX Overview
LVM
Logical Volume Manager (bundle BaseLVM) is the HP-UX default Volume Manager. It provides
the user with flexibility in configuring and managing mass storage resources. In HP-UX 11i v3,
the LVM kernel and commands are bundled with the core HP-UX product.
MirrorDisk/UX
MirrorDisk/UX (bundle B2491BA) is an optionally purchased HP-UX product to enable LVM
mirroring functionality.
Overview of Changes
The initial HP-UX 11i v3 release of LVM and MirrorDisk/UX was integrated with the new mass
storage stack, delivering significant performance, scalability, availability, and usability
enhancements. LVM was enhanced to support larger logical volumes, temporary quiescing of
volume groups, and striping with mirroring. Operations that previously required deactivation
or re-creation of a volume group—such as replacing a disk, resizing a LUN, and modifying
volume group characteristics—can now be performed online.
This September 2007 release of LVM and MirrorDisk/UX increases performance by performing
some operations in parallel, and increases availability by proactively polling alternate paths to
multi-pathed disks.
New and Changed Features in This Release
New Features
The following LVM features are new with the September 2007 release of HP-UX 11i v3:
• Parallel Opens of Physical Volumes: A new command line option, -T, has been added to
the vgchange command. This option controls the way LVM activates a volume group.
Normally, when a volume group is activated, LVM attaches the physical volumes one at a
time. On a system with multiple volume groups containing many physical volumes, this
can be time-consuming. Activating volume groups using vgchange with the -T option
attaches all the physical volumes in parallel.
See vgchange(1M) for more information.
• Proactive Polling of Alternate Links: A new command line option, -p, has been added to
the pvchange command. This option controls the way LVM monitors alternate links to a
multi-pathed physical volume.
By default, LVM proactively monitors the health of all configured links. If autoswitchback
is enabled (the default), this polling helps LVM detect and switch to a better link when it
becomes available.
If proactive polling of alternate links is undesirable, polling can be disabled using pvchange
-p n.
See pvchange(1M) for more information.
About this Document 5