HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes HP-UX 11i v3 (October 2010)
Table Of Contents
- HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes
- Table of Contents
- Logical Volume Manager and MirrorDisk/UX Release Notes
- About this document
- LVM and MirrorDisk/UX overview
- Known problems fixed in this version
- Known problems and limitations
- Known problems
- Auto pre-allocation occurs for all unsharing if distributed snapshot has 2 PVs
- Auto pre-allocated, distributed snapshot threshold considers all LV pre-allocated extents in PV
- Activation of Version 2.2 VG with space-efficient snapshots fails to properly mark snapshots as read-only when there are no free extents
- The lvextend command fails to increase the number of pre-allocated extents
- Limitations
- Known problems
- Installation requirements
- HP Insight Remote Support Software
- Compatibility issues
- Related documentation
- Software Availability in Native Languages

NOTE: Patches PHKL_36745, PHCO_36744, and PHCO_37939 resolve this compatibility
issue for HP-UX 11i v2. Installing these patches enables the creation and use of logical
volumes up to 16 TB.
• Striped Mirrors: Releases prior to HP-UX 11i v3 only support extent-based striping via the
-D option to lvcreate. If a logical volume using simultaneous mirroring and
non-extent-based striping is created on HP-UX 11i v3, attempts to import or activate its
associated volume group will fail on a previous HP-UX release. To import the volume group,
you must remove the incompatible logical volumes or reduce them to a single mirror.
NOTE: Patches PHKL_36745, PHCO_36744, and PHCO_37939 resolve this compatibility
issue for HP-UX 11i v2. Installing these patches enables the creation and use of striped
mirrors.
• Mirror Write Cache (MWC): When a volume group containing a logical volume using the
Mirror Write Cache is activated on HP-UX 11i v3, its Mirror Write Cache format is converted
to a new format. Importing or activating the volume group on a previous HP-UX release
does not recognize the new format and triggers a full resynchronization of the mirrors.
NOTE: Patch PHKL_36244 adds support for the new MWC format to HP-UX 11i v2.
Installing this patch avoids the unnecessary resynchronization.
As of this writing, larger logical volumes and striped mirrors are only available on HP-UX 11i
v3 and HP-UX 11i v2 (with patches). For up-to-the-moment information, contact your
Hewlett-Packard support representative or consult the Hewlett-Packard IT Resource Center site:
http://itrc.hp.com (Americas and Asia Pacific) or http://europe.itrc.hp.com (Europe) for LVM
patches.
Sharing volume groups in an HP Serviceguard cluster
To share a volume group in an HP Serviceguard cluster where the cluster nodes have different
versions of the LVM product installed, use the following guidelines:
• To share a version 2.1 volume group, you must install the HP-UX 11i v3 September 2008
release or above on all the cluster nodes.
• To share a 2.2 volume group, you must install the HP-UX 11i v3 March 2010 release or above
on all the cluster nodes.
• To use the Multi Node Online Reconfiguration (MORE) feature, you must install the HP-UX
11i v3 September 2009 release or above on all nodes of the cluster. Further, you can use
MORE only on version 2.1 or above volume groups.
NOTE: MORE does not operate in a cluster with both HP-UX 11i v3 September 2009 and
HP-UX 11i v3 March 2010 nodes. During a rolling update from HP-UX 11i v3 September
2009 to HP-UX 11i v3 March 2010, you cannot use MORE on the shared volume group.
Related documentation
LVM and MirrorDisk/UX manpages are installed with the product and provide the latest
documentation for all LVM commands and options. These manpages can be displayed via the
man command.
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