LVM Volume Group Versions

As of the September 2008 release of HP-UX 11i Version 3, LVM supports three versions of volume groups. All information and tasks in this document apply to all volume group versions except where noted.

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. When creating a new volume group, vgcreate defaults to Version 1.0.

Version 2.0 and Version 2.1 enable the configuration of larger volume groups, logical volumes, physical volumes, and other parameters. Version 2.1 is identical to Version 2.0, but allows a greater number of volume groups, physical volumes, and logical volumes. Version 2.x volume groups are managed exactly like Version 1.0 volume groups, with the following exceptions:

Version 2.x volume groups have simpler options to the vgcreate command. When creating a Version 2.x volume group, you specify only the extent size and the maximum size to which the volume group can grow. 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 more information on volume group creation, see “Creating a Volume Group”
Version 2.0 volume groups are not recognized on previous releases of HP-UX, including versions of HP-UX 11i Version 3 before March 2008. Version 2.1 volume groups are not recognized on previous releases of HP-UX, including versions of HP-UX 11i Version 3 before September 2008.
Version 2.x 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.x volume group.
Version 2.x volume groups do not support bootable physical volumes. You cannot add a physical volume created with pvcreate -B to a Version 2.x volume group.
Version 2.x 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.x volume groups.
Some HP-UX products do not support Version 2.x volume groups. For more information, see the HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes for your release.

Table 1-1 compares Version 1.0 and Version 2.x volume groups:

Table 1-1 LVM Volume Group Version Properties

	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^[1]	2048^[1]
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
LVM configuration file	`/etc/lvmtab`	`/etc/lvmtab_p`	`/etc/lvmtab_p`
Device file major number	64	128	128
^[1]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. For more information, see lvmadm(1M).

LVM Volume Group Versions

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