New and Changed Features in This Release

New Features

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

Version 2.0 Volume Groups

LVM and MirrorDisk/UX now support two 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 enables the configuration of larger volume groups, logical volumes, physical volumes, and other parameters. This version is transparently integrated with nearly all HP-UX subsystems and products. Version 2.0 volume groups can coexist with Version 1.0 volume groups on a server, and are managed exactly like Version 1.0 volume groups, with the following exceptions:

Version 2.0 volume groups have simpler options to the vgcreate command, as described in “Creating a Version 2.0 Volume Group”.
Version 2.0 volume groups are not recognized on previous releases of HP-UX, including versions of HP-UX 11i v3 before March 2008.
Version 2.0 volume groups do not support root, boot, swap, or dump logical volumes. The lvlnboot and lvrmboot commands display an error message if run on a Version 2.0 volume group.
Version 2.0 volume groups do not support bootable physical volumes. You cannot add a physical volume created with pvcreate -B to a Version 2.0 volume group.
Version 2.0 volume groups do not support disk sparing. Using the -z option to the vgextend or pvchange command displays an error message.
The pvck and vgmodify commands are not supported on Version 2.0 volume groups.
Some HP-UX products, as described in “Compatibility Issues”, do not support Version 2.0 volume groups.

Table 1 compares the configuration limits of Version 1.0 and Version 2.0 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
Maximum number of volume groups on a system	256	512
Maximum number of physical volumes in a volume group	255	511
Maximum number of logical volumes in a volume group	255	511
Maximum size of a physical volume	2 TB	16 TB
Maximum size of a volume group	510 TB	2048 TB
Maximum size of a logical volume	16 TB	256 TB
Maximum size of a physical extent	256 MB	256 MB
Maximum size of a stripe	32 MB	256 MB
Maximum number of stripes	255	511
Maximum number of logical extents per logical volume	65535	33554432
Maximum number of physical extents per physical volume	65535	16777216
Maximum number of mirror copies (MirrorDisk/UX product required)	2	5

You can display the volume group limits with the lvmadm command. For more information, see “lvmadm Command”.

Creating a Version 2.0 Volume Group

Version 2.0 volume groups are easier to configure at creation time than Version 1.0 volume groups. For Version 2.0 volume groups, the vgcreate command does not require maximum values for the number of physical volumes (-p), number of logical volumes (-l), or extents per physical volume (-e). Instead you must specify only the extent size (-s) and the maximum size to which the volume group can grow (-S). This gives LVM greater flexibility in managing space; you can use the same parameters for a volume group with many small PVs and for a volume group with a few large PVs. For example:

# vgcreate -V 2.0 -s pe_size -S vg_size /dev/vgname list_of_PVs

You must use all of the following options:

-V 2.0

Version 2.0 volume group

-s pe_size

Size of a physical extent in MB

-S vg_size

Maximum future size of the volume group

The size of a volume group is the sum of the user data space on all physical volumes assigned to the volume group. vg_size is not the size of the volume group at creation; it is the size to which the volume group can grow in the future. This value can be specified in megabytes, gigabytes, terabytes, or petabytes, by adding the character m, g, t, or p, respectively. For example, to specify a maximum size of two terabytes, use -S 2t.

The number of physical extents in a volume group has an architectural limit, so your choice of physical extent size affects the maximum size of the volume group. To display the maximum volume group size for a given physical extent size, use the -E option to vgcreate with the -s option. For example:

# vgcreate -V 2.0 -E -s 256
Max_VG_size=2p:extent_size=256m

Conversely, to display the minimum physical extent size for a given volume group size, use the -E option to vgcreate with -S. For example:

# vgcreate -V 2.0 -E -S 2t
Max_VG_size=2t:extent_size=1m

For more information about Version 2.0 volume groups, see the white paper LVM 2.0 Volume Groups in HP-UX 11i v3 described in “Related Documentation”.

lvmadm Command

This release introduces the lvmadm command, which displays the volume group limits shown in Table 1. For example, to show the Version 1.0 volume group limits, enter the following:

# lvmadm -t -V 1.0
--- LVM Limits ---
VG Version                  1.0
Max VG Size (Tbytes)        510
Max LV Size (Tbytes)        16
Max PV Size (Tbytes)        2
Max VGs                     256
Max LVs                     255
Max PVs                     255
Max Mirrors                 2
Max Stripes                 255
Max Stripe Size (Kbytes)    32768
Max LXs per LV              65535
Max PXs per PV              65535
Max Extent Size (Mbytes)    256

For more information, see lvmadm(1M).

Changed Features

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

vgcreate Autocreation of Volume Group File

The vgcreate command now automatically creates the device file /dev/vgname/group to manage the volume group, regardless of the volume group version.

If you want to specify the minor number of the group file, create /dev/vgname/group before running the vgcreate command. To create the volume group device file, follow these steps:

Create a directory for the volume group. For example:
# mkdir /dev/vgname
By convention, vgname is vgnn, where nn is a unique number across all volume groups. However, you can choose any unique name up to 255 characters.
Create a device file named group in the volume group directory with the mknod command. For example:
# mknod /dev/vgname/group c major minor
The c following the device file name specifies that group is a character device file.
major is the major number for the group device file. For a Version 1.0 volume group, it is 64. For a Version 2.0 volume group, it is 128.
minor is the minor number for the group file in hexadecimal. For a Version 1.0 volume group, minor has the form 0xnn0000, where nn is a unique number across all Version 1.0 volume groups. For a Version 2.0 volume group, minor has the form 0xnnn000, where nnn is a unique number across all Version 2.0 volume groups.
For more information on mknod, see mknod(1M); for more information on major numbers and minor numbers, see HP-UX System Administrator's Guide: Logical Volume Management.

vgremove Removal of Volume Group File

The vgremove command now supports a -X option to remove the volume group device files in /dev.

Display Enhancements

The lvdisplay, pvdisplay, vgdisplay and vgcfgrestore commands display additional information.

vgdisplay displays the volume group version, the maximum size to which the volume group can grow, and the maximum number of physical extents. For example:

# vgdisplay vg00
--- 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

lvdisplay displays the logical extent status for up to six physical extents, to accommodate the increased mirror copies for Version 2.0 volume groups.

pvdisplay with the -d option displays the offsets to the start and end of the user data in 1KB blocks from the beginning of the physical volume. For example:

# pvdisplay -d /dev/disk/disk201_p2
--- Physical volumes ---
PV Name                     /dev/disk/disk201_p2
VG Name                     /dev/vg00
PV Status                   available
Allocatable                 yes
VGDA                        2
Cur LV                      7
PE Size (Mbytes)            16
Total PE                    4319
Free PE                     1
Allocated PE                4318
Stale PE                    0
IO Timeout (Seconds)        default
Autoswitch                  On
Data Start                  2912
Data End                    70765408
Boot Disk                   yes
Relocated Blocks            0
Proactive Polling           On

In this example, physical extent 0 starts at block 2912 and the last physical extent ends at block 70765408.

vgcfgrestore with the -v option displays the volume group version. For a Version 2.0 volume group, it displays the maximum size to which the volume group can grow. For example:

# vgcfgrestore -n /dev/vg1 -v -l
Volume Group Configuration information in "/etc/lvmconf/vg1.conf"
VG Name /dev/vg1
 ---- Physical volumes : 1 ----
      PV         Type         Size (kb)          Start (kb)   PVkey
      disk23   Non-Boot         512640           1024        0

max_pv 511  max_pe 256 max_lv 511 vg_version 2.0 vg_size 1g

MirrorDisk/UX Operating Environment

MirrorDisk/UX is now delivered as an optional product in the HP-UX 11i v3 BOE, VSE-OE, HA-OE, and DC-OE.

Deprecated or Obsolete Features

The following features are deprecated or obsolete with the March 2008 release of HP-UX 11i v3:

Obsolete Command Options for Version 2.0 Volume Groups

The following LVM command options are obsolete. Using them with Version 2.0 volume groups either displays an error message and fails, or displays a warning message and ignores the option.

vgcfgrestore: -F option displays a warning.
vgcreate: -e, -l, -p, -f options all display an error.
vgextend: -f and -z n options display a warning.
pvchange, vgextend: -z y option displays an error.
pvchange: -z n option displays a warning.
pvcreate: -s option displays a warning.
lvcreate, lvextend, lvreduce, lvchange: -r option displays a warning.