HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes HP-UX 11i v3 (September 2010)

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 2010 release of HP-UX 11i v3.
LVM and MirrorDisk/UX overview
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 (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. Volume group availability was improved: resizing a
LUN and modifying volume group characteristics no longer required the volume group to be
recreated, and replacing a disk could be done online.
The September 2010 release of LVM and MirrorDisk/UX provides enhancements to logical volume
snapshots. In addition, this release provides support for cluster Device Special Files (cDSF) and an
enhancement to the vgchange command when operating in a cluster environment.
New and changed features in this release
New features
The following LVM features are new with the September 2010 release of HP-UX 11i v3:
Cluster Device Special Files
This release supports the use of cluster device special files (cDSF). This feature is effective only in
a cluster environment and requires that you install HP Serviceguard A.11.20 and patch it to support
cluster-wide device special files.
Changed features
The following features have changed in the September 2010 release of LVM and MirrorDisk/UX:
Snapshot enhancements
Snapshot enhancements enable you to do the following:
• Automatically increase the pre-allocated extents when the threshold value is reached. This
prevents space-efficient snapshots from becoming inoperative or over commit.
• Change the size and mirror count of a logical volume that has associated snapshot logical
volumes. However, you cannot reduce the size of this logical volume if it has at least one
space-efficient snapshot logical volume associated with it.
In addition, the enhancements provide improved resynchronization performance for mirrors of
snapshot logical volumes.
4 Logical Volume Manager and MirrorDisk/UX Release Notes