HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes (September 2009)

VxVM 4.1 Commands
Several VxVM 4.1 commands check whether a specified disk device is being used by LVM before
overwriting it. For these commands to correctly check whether a device is part of a Version 2.x
volume group, you must install the following patch:
• PHCO_37836
Required Disk Space
Because LVM is installed with the HP-UX 11i v3 operating environment, it consumes no additional
disk space.
MirrorDisk/UX consumes no additional disk space aside from a license key.
Compatibility Issues
This release is specific for HP-UX 11i v3 (B.11.31). The following compatibility issues exist in the
September 2009 release of HP-UX 11i v3.
Version 2.1 Volume Groups
• Version 2.1 volume groups are not recognized on previous releases of HP-UX, including
versions of HP-UX 11i v3 prior to the September 2008 release. Version 1.0 volume groups
are supported on all supported versions of HP-UX, including 11i v1, 11i v2, and 11i v3.
• The following HP-UX product does not currently support Version 2.0 or Version 2.1 volume
groups:
— HP Process Resource Manager (HP PRM)
This product plans to add support of Version 2.x volume groups. For the most recent
information on this products, see the IT Resource Center (ITRC) at http://itrc.hp.com, or
consult the release notes for the specific product.
Encrypted Volume and File System (EVFS) v1.1 and greater supports Version 2.x volume groups.
Moving from HP-UX 11i v2 to HP-UX 11i v3
If you are migrating a system from HP-UX 11i v2 to HP-UX 11i v3, see the LVM migration white
paper described in “Related Documentation”. It contains information on migrating an LVM
configuration from the legacy naming model to the agile naming model.
Existing LVM configurations created on HP-UX 11i v2 continue to work on HP-UX 11i v3 under
the legacy naming model. However, there is a change in behavior for Alternate Links (PVLinks):
In HP-UX 11i v3, management of multipathed devices is available outside of LVM using the next
generation mass storage stack. By default, the next generation mass storage stack distributes I/O
requests across all available paths to a multipathed disk, even when using legacy device special
files. Using LVM with persistent or legacy device special files might cause I/O requests to be sent
across alternate links, even if the links are not configured as PVLinks; this does not introduce
any errors, but it does differ from PVLink behavior in previous releases.
When using LVM configuration commands on legacy device special files, LVM does not select
an alternate path if the path corresponding to the specified device special file is unavailable,
unless the unavailable path and the alternate path are configured as part of an active volume
group.
When using LVM configuration commands on persistent device special files, LVM succeeds if
at least one of the paths to the device is available.
HP recommends converting volume groups with multipathed disks to persistent device special
files and using native multipathing, as described in the migration white paper in “Related
Documentation”.
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