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

configured with such striped mirrors cannot be imported on releases before HP-UX 11i v3;
see the “Compatibility Issues” section.
To maximize data integrity for striped mirrors, LVM enforces a strict allocation policy; that
is, mirrored physical extents must be allocated on different physical volumes. This forces
the physical extents used by all the replicas of a strip onto different physical volumes.
Changed Features
The following features have changed from the previous release of LVM:
• Increased logical volume size: LVM now supports logical volumes up to 16 terabytes (16
TB) in size, an increase from 2 TB in previous releases. Logical volumes larger than 2 TB
may not be usable on previous releases; see the “Compatibility Issues” section.
• Display enhancements: The lvdisplay, pvdisplay, vgdisplay, and vgscan commands
all support long hostnames. Those commands also support a new -F option to print in a
format more easily parsed by user scripts. The pvdisplay command has a new -l option
to display if a disk is under LVM control; the existing -d option displays if a physical volume
is a bootable physical volume.
• vgscan enhancements: In addition to support of the mass storage stack, vgscan has new
-f and -k options.
By default, the vgscan command does not modify or supplement the /etc/lvmtab file
entries for volume groups that already have entries. The new -f option forces an update of
the existing entries for the specified volume group.
By default, the vgscan command scans the I/O configuration searching for LVM physical
volumes, which can be a time-consuming operation. The new -k option reads the LVM data
structures in kernel memory and populates the /etc/lvmtab file based on that data.
Deprecated or Obsolete Features
The following features are deprecated or obsolete with the HP-UX 11i v3 release of LVM:
• Bad Block Relocation: LVM no longer performs software bad block relocation, as modern
disks and disk arrays handle such relocation in their own hardware. Existing software
relocation information is honored, unless the physical volume is larger than 256 GB.
• Kernel Tunable maxvgs: The tunable parameter maxvgs is obsolete. LVM can now create
up to 256 volume groups dynamically. Any attempts to modify maxvgs using the kctune
command cause the following error message:
ERROR: There is no tunable named 'maxvgs'.
Known Problems and Limitations
No known problems were identified for this release of LVM and MirrorDisk/UX.
Known Problems and Limitations 7