HP-UX System Administrator's Guide: Logical Volume Management (5900-3028, March 2013)

6. Initialize the disk as a physical volume using the pvcreate command. For example:
# pvcreate /dev/rdisk/disk3
Use the character device file for the disk.
If you are initializing a disk for use as a boot device, add the -B option to pvcreate to
reserve an area on the disk for a LIF volume and boot utilities. If you are creating a boot disk
on an HP Integrity server, make sure the device file specifies the HP-UX partition number (2).
For example:
# pvcreate -B /dev/rdisk/disk3_p2
NOTE: Version 2.0 and 2.1 volume groups do not support bootable physical volumes. Do
not use the -B option if the disk will be used in a Version 2.0 or 2.1 volume group.
After a disk is initialized, it is called a physical volume.
Creating a Volume Group
To create a volume group, use the vgcreate command. The options differ depending on whether
you are creating a Version 1.0 volume group or a Version 2.x volume group.
Creating the Volume Group Device File
As of the March 2008 release of HP-UX 11i Version 3, the vgcreate command automatically
creates the device file /dev/vgname/group to manage the volume group, regardless of the
volume group version. If you are using an HP-UX release before March 2008, or if you want to
specify the minor number of the group file, you must create /dev/vgname/group before running
the vgcreate command.
If the group file does not exist and vgcreate can not create it, vgcreate displays the following
message:
vgcreate: "/dev/vgname/group": not a character device.
To create the volume group device file, follow these steps:
1. 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.
2. Create a device file named group in the volume group directory with the mknod command.
For example:
# mknod /dev/vgname/group c major 0xminor
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.x 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.x volume group, minor has the form 0xnnn000, where nnn
is a unique number across all Version 2.x volume groups.
For more information on mknod, see mknod(1M); for more information on major numbers
and minor numbers, see “Device Number Format” (page 15).
Creating a Version 1.0 Volume Group
To create a Version 1.0 volume group, use the vgcreate command, specifying each physical
volume to be included. For example:
# vgcreate /dev/vgname /dev/disk/disk3
44 Administering LVM