How to mirror a normal volumegroup?

[expertone]

Can any body of you tell me how to craet mirroring of a normal volumegroup.

P.S. This post has been splitted off from HP-UX > general to HP-UX-LVM and VxVM, and edited its subject - HP Forums Moderator

[Robert_Jewell]

Two things you should know to start....

1)  The mirroring software for HP-UX LVM is Mirrordisk/UX and is a licensed product.  Do you have this installed?

       How to check:

           Run # lvextend

           Do you see the following in the usage message?

           -m MirrorCopies

           If so, then you have hte Mirrordisk license installed.  If not, then you do not and cannot perform LVM mirroring until the license is obtained.

2)  Mirroring is done at the logical volume level (not the volume group level).

So, given the above is understood, I can offer the following....

By "normal volume group" I assume you a volume group that is not a part of the root disk?   I also assume you have a new disk or LUN that you wish to use (not currently being used in another volume) and that the volumes you wish to mirror already exist and have data?  If so, then the basic process is as follows:

 - Identify the logical volume you wish to mirror.  For this example Ill use /dev/vg01/lvol1.

 - Identify the phsyical volume (disk or LUN) that you wish to create the mirrors on.  For this example Ill use /dev/dsk/c1t0d0.

 - Create the phsyical volume (this places the LVM headers on the disk drive/LUN):

      # pvcreate /dev/rdsk/c1t0d0

- Extend the volume group configuration to this disk

     # vgextend /dev/vg01 /dev/dsk/c1t0d0

- Create the mirror of the logical volume to this disk

     # lvextend -m 1 /dev/vg01/lvol1 /dev/dsk/c1t0d0

     The "-m 1" option creates one mirror of the volume specified onto the physical volume specified.  

      Do this for each logical volume you wish to mirror.

- Check on the configuration with the vgdisplay and lvdisplay commands:

     # vgdisplay -v vg01

     Look for the phsyical volumes listed.

     # lvdisplay -v /dev/vg01/lvol1 | more

     Look for: 

Mirror copies               1

and..

   --- Distribution of logical volume ---
   PV Name            LE on PV  PE on PV
   /dev/dsk/c0t0d0    4340      4340
   /dev/dsk/c1t0d0    4340      4340

See the man pages for any of these commands for more details and other options.

-Bob

[Robert_Jewell]

See the folllowing for more details about LVM:

This document is specific for HP-UX 11i v3 (11.31), but much of it applies to older versions.

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02023734/c02023734.pdf

-Bob