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How to create a Volume Group

Abstract

This article explains how to create Logical Volume Manager (LVM) Volume Groups using the Command Line Interface (CLI). Other available methods include System Administration Manager (SAM) and System Management Homepage.

With the March 2008 release of HP-UX 11i v3 (11.31) a new LVM version 2.0 was included, that provides larger volume groups and physical volume support among another features. Newer subversion, like 2.1 and 2.1 has been in the following year to extends some of the limits.

Only the required LVM commands are presented in this article. Is the responsability of the system Administrator to determine which Physical Volumes are available to create the Volume Group.

Contents


LVM 1.0 Volume Group

1. Check the available minor numbers for the group device file:

# ll /dev/*/group

2. Create the directory where the volume group would be stored, and as a good practice, assign the permissions with the same command.

# mkdir -m 755 /dev/<vgname>

3. Create the device special file (dsf). Use the next available minor number.

# mknod /dev/<vgname>/group c 64 0x##0000

4. Create the Volume Group, adding at least one physical volume.

# vgcreate /dev/<vgname> /dev/dsk/c#t#d# ...
NOTE: If you didn't include all physical volumes you were intending to use in the same command, you can do it using the vgextend command:
# vgextend /dev/<vgname> /dev/dsk/c#t#d# ...

LVM 2.x Volume Group

The 2.0 volume groups became available with the March 2008 release of HP-UX 11i v3 (11.31) and the 2.1 volume groups with the 11i v3 2008 September release. Prior to the March 2008 release, only version 1.0 volume groups were available.
Usage of Agile Device Special Files to address the Physical Volumes is highly recommended.

1. Check the available minor numbers for the group device file:

# ll /dev/*/group

2. Create the directory where the volume group would be stored, and as a good practice, assign the permissions with the same command.

# mkdir -m 755 /dev/<vgname>

3. Create the device special file (dsf). Use the next available minor number. Note that on LVM 2.x volume groups, three HEX positions instead of two are use to set the minor number volume group ID.

# mknod /dev/<vgname>/group c 128 0x###000

4. Create the Volume Group, adding at least one physical volume.

# vgcreate /dev/<vgname> /dev/disk/disk# ...
NOTE: If you didn't include all physical volumes you were intending to use in the same command, you can do it using the vgextend command:
# vgextend /dev/<vgname> /dev/disk/disk# ...

Reference

Authors

This page was last modified on 3 August 2011, at 18:58. This page has been accessed 5,953 times.