New and Changed Features in This Release

New Features

The following LVM features are new with the September 2008 release of HP-UX 11i v3:

Version 2.1 Volume Groups

LVM and MirrorDisk/UX now support three versions of volume groups.

Version 1.0 is the version supported on all current and previous versions of HP-UX 11i. The procedures and command syntax for managing Version 1.0 volume groups are unchanged from previous releases, except for the enhancements described in “Changed Features”. When creating a new volume group, vgcreate defaults to Version 1.0.

Version 2.0, introduced in the March 2008 release of HP-UX 11i v3, enables the configuration of larger volume groups, logical volumes, physical volumes, and other parameters. Version 2.1, introduced in this release, is similar to Version 2.0, but allows an even greater number of volume groups, physical volumes, and logical volumes. Version 2.1 volume groups can coexist with Version 2.0 and Version 1.0 volume groups on a server, and are managed exactly like Version 2.0 volume groups, with the following exceptions:

Version 2.1 volume groups are not recognized on previous releases of HP-UX, including versions of HP-UX 11i v3 before September 2008.
Version 2.1 supports up to 2048 volume groups. However, this limit is shared between Version 2.0 and Version 2.1 volume groups.^*

Table 1 compares the configuration limits of Version 1.0, Version 2.0, and Version 2.1 volume groups. These limits are independent — for example, a server can be configured with 256 Version 1.0 volume groups and 512 Version 2.0 volume groups at the same time.

Table 1 LVM Volume Group Version Limits

	Version 1.0 Volume Groups	Version 2.0 Volume Groups	Version 2.1 Volume Groups
Maximum number of volume groups on a system	256	512^*	2048^*
Maximum number of physical volumes in a volume group	255	511	2048
Maximum number of logical volumes in a volume group	255	511	2047
Maximum size of a physical volume	2 TB	16 TB	16 TB
Maximum size of a volume group	510 TB	2048 TB	2048 TB
Maximum size of a logical volume	16 TB	256 TB	256 TB
Maximum size of a physical extent	256 MB	256 MB	256 MB
Maximum size of a stripe	32 MB	256 MB	256 MB
Maximum number of stripes	255	511	511
Maximum number of logical extents per logical volume	65535	33554432	33554432
Maximum number of physical extents per physical volume	65535	16777216	16777216
Number of mirror copies (MirrorDisk/UX product required)	0–2	0–5	0–5

^* The limit of 2048 volume groups is shared between Version 2.0 and Version 2.1 volume groups. Volume groups of both versions can be created with volume group numbers ranging from 0-2047. However, the maximum number of Version 2.0 volume groups that can be created is 512.

You can display the volume group limits with the lvmadm command.

Boot Disk Configuration Self-Healing

If the device special file for your LVM boot disk changes because its hardware path changed, LVM scans for the boot disk during the boot process. After successfully booting, LVM automatically updates the LVM configuration files /etc/lvmtab and /etc/lvmtab_p, as well as the LVM metadata on each bootable disk in the root volume group, with the new boot path so that future system boots will not need to scan. This behavior is configurable, and is enabled by default. To disable it, edit /etc/lvmrc and change the AUTO_BOOT_MIGRATE flag to 0.

Changed Features

The following features have changed in the September 2008 release of LVM and MirrorDisk/UX:

Display Enhancements

The vgdisplay, pvdisplay, and lvmadm commands display additional information.

vgdisplay with the -V VG_vers option displays the volume group information for all volume groups of the specified version. For example:

# vgdisplay -V 1.0
--- Volume groups ---
VG Name                     /dev/vg00
VG Write Access             read/write
VG Status                   available
Max LV                      255
Cur LV                      7
Open LV                     7
Max PV                      16
Cur PV                      1
Act PV                      1
Max PE per PV               4328
VGDA                        2
PE Size (Mbytes)            16
Total PE                    4319
Alloc PE                    4318
Free PE                     1
Total PVG                   0
Total Spare PVs             0
Total Spare PVs in use      0
VG Version                  1.0
VG Max Size                 1082g
VG Max Extents              69248

pvdisplay with the new -u option displays the Data Start and End, and if the physical volume is bootable. This must be used with the existing -l option. For example:
# pvdisplay -l /dev/disk/disk34_p2 /dev/disk/disk34_p2:LVM_Disk=yes # pvdisplay -l -u /dev/disk/disk34_p2 /dev/disk/disk34_p2:LVM_Disk=yes:Data_Start=2912:Data_End=34638688:Bootable=yes
In this example, physical extent 0 starts at block 2912 and the last physical extent ends at block 34638688, and the physical volume is bootable.
lvmadm with the new -l VG_vers option displays the LVM configuration in the /etc/lvmtab and /etc/lvmtab_p files for the specified volume group version. For example:
# lvmadm -l 1.0 --- Version 1.0 volume groups --- VG Name /dev/vg00 PV Name /dev/disk/disk34_p2
This is a supported replacement for running the command strings /etc/lvmtab.

pvmove Enhancements

The pvmove command has several new features.

pvmove supports moving a range of extents. For example, to move extents 25 through 100 from /dev/disk/disk32 to /dev/disk/disk55, use this command:
# pvmove /dev/disk/disk32:25-100 /dev/disk/disk55
pvmove supports moving extents from the end of a physical volume. For example, to move the last 5 extents from /dev/disk/disk32 to another physical volume, use this command:
# pvmove -e 5 /dev/disk/disk32
pvmove supports moving extents to a specific location on the target physical volume. For example, to move extents from /dev/disk/disk32 to /dev/disk/disk55, starting at physical extent 50 on /dev/disk/disk55, use this command:
# pvmove /dev/disk/disk32 /dev/disk/disk55:50
pvmove supports striped logical volumes and striped mirrored logical volumes.
pvmove supports a new -p option to preview physical extent movement details without performing the move.

For more information, see pvmove(1M).

vgmodify Online LUN Expansion

The vgmodify command supports LUN expansion on a Version 1.0 volume group without deactivating the volume group. To reconfigure an activated volume group to take advantage of a physical volume size increase, use the –E and –a options to vgmodify. For example, if the physical volume /dev/disk/disk32 in volume group vg02 has been expanded, use the following command to add physical extents to it:

# vgmodify -a -E /dev/vg02 /dev/rdisk/disk32

For more information, see vgmodify(1M).

Deprecated or Obsolete Features

No LVM or MirrorDisk/UX features are deprecated or obsolete in the September 2008 release of HP-UX 11i v3.