vgcreate.1m (2010 09)

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vgcreate(1M) vgcreate(1M)

For volume groups versions 2.0 and higher, this is a required parameter. See

lvm(7) for more information on extent sizes on volume groups versions 2.0 and

higher.

-S vg_size Only applicable to volume groups versions 2.0 and higher. Sets the maximum

size of the volume group. The maximum size is the total size of all physical

extents in the volume group.

The unit for

vg_size is speciﬁed as a sufﬁx. The recognized values for the

sufﬁx are m (megabytes), g (gigabytes),

t (terabytes), and p (petabytes). If no

sufﬁx is supplied, then

m (megabytes) is assumed. A

vg_size of 512 tera-

bytes would be speciﬁed as 512t. Only whole numbers are accepted.

The maximum supported vg_size is 2p.

NOTE: If the product of the physical extent size and the total number of phy-

sical extents for the physical volumes speciﬁed on the

vgcreate command

line is greater than the value speciﬁed, then vg_size is upgraded to take

account of this size and an informational message is issued.

-U unshare_unit Only applicable to volume group 2.2 and higher. Sets the unit at which data

will be unshared between a logical volume and its snapshots. unshare_unit is

expressed in units of kilobytes (KB) and the supported values are 512, 1024,

2048, and 4096.

This is an optional parameter and if not speciﬁed, the default value of 1024

KB is assumed. The unshare_unit cannot be greater than the physical extent

size of the volume group. See lvm(7) for information about snapshots.

-x extensibility Set the allocation permission for adding physical extents on the physical

volumes speciﬁed by the pv_path parameter. extensibility can have one of the

following values:

y Allow allocation of additional physical extents on the physical volume.

This is the default.

n Prohibit allocation of additional physical extents on the physical volume.

Logical volumes residing on the physical volume can still be accessed

after the volume group has been activated by the

vgchange -a y com-

mand.

-E Only applicable to volume groups versions 2.0 and higher. Instead of creating

a volume group, this option will display the maximum VG size based on the

given physical extent size (-s option) or minimum physical extent size based

on the max VG size (-S option). Either -S or -s must be supplied.

The output will be in the form:

Max_VG_size=x:extent_size=

y, where

x and y are determined by

-s or -S. See the Extent Sizing for Volume Group

Version 2.0 and Higher section in lvm(7) for more information.

Alternate Links (PVLinks)

In this release of HP-UX, LVM continues to support Alternate Links to a device to allow continued access

to the device, if the primary link fails. This multiple link or multipath solution increases data availabil-

ity, but does not allow the multiple paths to be used simultaneously.

There is a new feature introduced in the Mass Storage Subsystem on this version of HP-UX that also sup-

ports multiple paths to a device and allows access to the multiple paths simultaneously. The Mass

Storage Subsystem will balance the I/O load across the valid paths. This new multi-path behavior is

enabled and disabled through the use of the scsimgr command. See scsimgr (1M) for details.

It is no longer required or recommended to conﬁgure LVM with alternate links. However, it is possible to

maintain the traditional LVM behavior. To do so, both of the following criteria must be met:

• Only the legacy device special ﬁle naming convention is used in the volume group conﬁguration.

• The scsimgr command is used to disable the Mass Storage Subsystem multipath behavior.

EXTERNAL INFLUENCES

HP-UX 11i Version 3: September 2010 − 3 − Hewlett-Packard Company 3