Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP
More options
HP.com home
HP-UX System Administrator's Guide: Logical Volume Management: HP-UX 11i Version 3 > Chapter 3 Administering LVM

Hardware Issues


Technical documentation

Complete book in PDF
» Feedback
Content starts here

 » Table of Contents

 » Glossary

 » Index

This section describes hardware-specific issues dealing with LVM.

Integrating Cloned LUNs

Certain disk arrays can create clones of their LUNs. For example, the HP XP product enables you to split off a set of LUNs, called Business Copies (BCs), which are copies of existing LUNs.

Cloned disks have the same information in their LVM headers as the original disks, which violates LVM's requirement that each disk have a unique identifier. To make the cloned disks usable with LVM, use the vgchgid command to change their volume group identifier (VGID).

All of the physical volumes to be changed must belong to the same volume group. Therefore, if you are changing multiple physical volumes, specify all of them in a single invocation of vgchgid. Otherwise, they are assigned different VGIDs.

For example, you have a volume group containing four physical volumes and need to create a BC for each physical volume. If you run vgchgid on only two BCs, vgchgid modifies the VGID on those two BCs. If you then run vgchgid again with all four BCs, vgchgid reports that they belong to different volume groups. To correct this, you can either run vgchgid on the two unmodified BCs and then use the four BCs in two separate volume groups, or you can merge back the two modified BCs and split them off again before finally running vgchgid with all four BCs.

After running vgchgid on a set of physical volumes, use vgimport to import them into a new volume group. For example:

  1. Make BC copies and create new device files using the instructions for the array.

  2. Change the VGID on the cloned disks as follows:

    # vgchgid /dev/rdisk/disk49 /dev/rdisk/disk50
  3. If you are using an HP-UX release before March 2008, create the volume group group file using the procedure in “Creating the Volume Group Device File”.

  4. Import the physical volumes as follows:

    # vgimport /dev/vg04 /dev/rdisk/disk49 /dev/rdisk/disk50
  5. Back up the volume group configuration information as follows:

    # vgcfgbackup /dev/vg04
  6. Activate the volume group as follows:

    # vgchange -a y /dev/vg04
Printable version
Privacy statement Using this site means you accept its terms Feedback to webmaster
© 2008 Hewlett-Packard Development Company, L.P.