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vgcreate(8)
NAME
vgcreate - Creates a volume group
SYNOPSIS
/usr/sbin/vgcreate [-x Extensibility] [-e MaxPhysicalExtents] [-l
MaxLogicalVolumes] [-p MaxPhysicalVolumes] [-s PhysicalExtentSize] [-v
VGDA] VolumeGroupName PhysicalVolumePath ...
DESCRIPTION
Note
This command is no longer supported on Digital UNIX systems.
Features formerly provided by the Logical Volume Manager (LVM)
are now provided by the Logical Storage Manager (LSM). Existing
LVM volumes must be migrated to LSM, using an encapsulation
process. For information about moving LVM volumes to LSM, see
the vollvmencap(8) reference page and the manual Logical Storage
Manager.
The vgcreate command creates a new volume group. VolumeGroupName is a
symbolic name for the volume group and must be used by all references to
it. VolumeGroupName is the path to a directory-entry under /dev which
must contain a character special file named group. Except for the group
entry, the directory VolumeGroupName should not contain any other entries.
The vgcreate command leaves the volume group in an active state.
Before assigning a physical volume to a volume group, the physical volume
has to be created with the pvcreate command.
If vgcreate fails to install the first specified physical volume into the
volume group, the volume group is not created. If, for any reason, one of
the remaining specified physical volumes cannot be installed into the
volume group, an error message is printed, but the installation continues
to the end of the list of physical volumes.
FLAGS
-x Extensibility
Sets the allocation permission for adding physical extents on the
physical volumes specified by the PhysicalVolumePath parameter.
The Extensibility parameter is represented by one of the
following:
y Allows the allocation of additional physical extents on
the physical volume. (The default.)
n Prohibits the allocation of additional physical extents
on the physical volume. The logical volumes that reside
on the physical volume can still be accessed, after the
volume group has been activated with the vgchange -a y
command.
-e MaxPhysicalExtents
Sets the maximum number of physical extents that can be allocated
from any of the physical volumes in the volume group. The
default is 1016.
-l MaxLogicalVolumes
Sets the maximum number of logical volumes that the volume group
is allowed to contain. The default is 255.
-p MaxPhysicalVolumes
Sets the maximum number of physical volumes that the volume group
is allowed to contain. The default is 32.
-s PhysicalExtentSize
Sets the number of megabytes in each physical extent, where
PhysicalExtentSize is expressed in units of megabytes from 1
through 256. PhysicalExtentSize must be equal to a power of 2
(for example, 1, 2, 4, 8). The default is 1 megabyte.
-v VGDA This option allows you to specify if a VGDA (Volume Group
Descriptor Area) of the volume group has to be stored on the
physical volume(s). A VGDA is always stored on the first
physical volume specified. This flag impacts only the second,
third, and so on, physical volumes specified. VGDA is
represented by one of the following:
y Allows the creation of a VGDA on the physical volume.
(The default.)
n Prohibits the creation of a VGDA on the physical
volume.
EXAMPLES
This section contains Digital device-specific examples.
1. To create a volume group named /dev/my_vg that contains three physical
volumes, with extent size set to 2 megabytes, enter:
vgcreate -s 2 /dev/my_vg /dev/rz3c /dev/rz5c /dev/rz6c
If the directory /dev/my_vg exists with the character special file
group, the volume group will be created.
2. To create a volume group named /dev/user_vg that can contain a maximum
of three logical volumes, with extent size set to 8 megabytes, enter:
vgcreate -l 3 -s 8 /dev/user_vg /dev/rz3c
A new volume group, /dev/user_vg is created with extent size equal to
8 megabytes.
FILES
/usr/sbin/vgcreate
Specifies the command path
RELATED INFORMATION
Commands: pvcreate(8), vgchange(8), vgdisplay(8), vgextend(8), vgreduce(8)