HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes HP-UX 11i v3 (March 2012)

Severity: Serious
Corrective Action: If a cluster has been stopped and restarted multiple times incurring
noticeable memory leaks, then reboot the node to recover the lost
memory.
“vgchange -c [y|n]” does not safe guard against cluster-ID corruption
Defect ID: QXCR1001161003
Problem: When the volume group is activated in shared mode in other nodes,
running ‘vgchange –c n’ on any node in SLVM environment would
leave the cluster in a state that prevents the newly joining node to
activate the volume group.
Severity: Serious
Corrective Action: Change the physical volume’s properties on the other node in the
cluster after activating the volume group in exclusive mode. Before
performing this step, the volume group must be deactivated in all the
other nodes except this node.
Limitations
This section provides a list of limitations as known to HP at time of publication.
• Logical volumes that have snapshots associated with them might experience an increase in
latencies associated with writes. This is also applicable for writes on (writable) snapshots
themselves.
• With the HP-UX 11i v3 September 2010 Update release, when the number of extents remaining
in a space-efficient snapshot logical volume’s pre-allocated pool falls beyond a certain internally
computed threshold, by default, LVM tries to increase the pre-allocated pool size by threshold
value. This does not guarantee that snapshot will not become over-commit. For example, if
the I/O rate is faster than auto pre-allocation, the snapshot becomes over-commit.
If auto pre-allocation is manually disabled, a message is logged in the syslog. This message
is displayed to inform you that further unsharing of data between the snapshot and its successors
might end up depleting the extents in the pre-allocated pool and lead to the snapshot and its
predecessors being marked as inoperative. As soon as you see this message in the syslog,
you must increase the pre-allocated extent pool size for the snapshot logical volume.
• For more limitations on snapshots, see the Using LVM Logical Volume Snapshots white paper.
Installation requirements
This section describes the installation requirements for this release.
Required hardware
LVM and MirrorDisk/UX have no hardware requirements beyond the requirements of the HP-UX
11i v3 operating system. Both products run on all supported HP 9000 and HP Integrity servers.
Required software
Because LVM is installed with the HP-UX 11i v3 operating environment, there are no software
requirements beyond the requirements of the HP-UX 11i v3 operating system. MirrorDisk/UX
requires the BaseLVM™ product.
Required patches
In HP-UX 11i v3, LVM and MirrorDisk/UX do not require any software patches.
For each of the following subsystems, you can download patches from the following website:
Installation requirements 7