HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes (March 2008)

• 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” (page 12), 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 2.0
Volume Groups
Version 1.0
Volume Groups
512256Maximum number of volume groups on a system
511255Maximum number of physical volumes in a volume group
511255Maximum number of logical volumes in a volume group
16 TB2 TBMaximum size of a physical volume
2048 TB510 TBMaximum size of a volume group
256 TB16 TBMaximum size of a logical volume
256 MB256 MBMaximum size of a physical extent
256 MB32 MBMaximum size of a stripe
511255Maximum number of stripes
3355443265535Maximum number of logical extents per logical volume
1677721665535Maximum number of physical extents per physical volume
52Maximum number of mirror copies (MirrorDisk/UX product required)
You can display the volume group limits with the lvmadm command. For more information, see
“lvmadm Command” (page 7).
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.
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