Mirroring an AIX volume group (e.g. for machines with 2 system disks)

1. configure additional disks (if not yet recognized)

     smit -C
     Devices - Install/Configure Devices Added After IPL
     

2. add disks to existing VG's

     smit -C
     System Storage Management - LVM - Volume Groups - Set Characteristics ... - Add a Physical Volume to a Volume Group
     

3. Mirror the volume group,
   
   • Method 1 (traditional), by LV
     

       smit -C
       System Storage Management - LVM - Logical Volumes - Set Characteristics ... - Add a Copy to a Logical Volume
       

     selection list via F4 key. (for rootvg the LVs hd6,hd8,hd4,hd2,hd9var,hd3,hd1,... have to be selected, unfortunately one after the other separately. hd5 must not be mirrored this way) Fill the following entries and submit:

       NEW TOTAL number of logical partition               2
       SYNCHRONIZE the data in the new                     yes
                   logical partition copies?
       

     Be patient, this might take some time because data has to be copied to the mirror disk.
     For a rootvg (only) the mirror copy must be made bootable

       mklv -y hd51 -t boot -a e rootvg 2 hdiskx
       bosboot -a -l /dev/hd51 -d /dev/hdiskx
       bootlist -m normal hdisky hdiskx
       

     where hdiskx is the additional physical volume holding the mirror and hdisky the original (x,y = 0..n )
   • Method 2 (new, faster), by VG
     

       smitty 
       System Storage Management - LVM - Logical Volumes -  Volume Groups - Mirror a Volume Group
       PHYSICAL VOLUME names       [hdiskx]
       Number of COPIES            2
       

     Be patient, this might take some time because data has to be copied to the mirror disk. As suggested, for a rootvg (only) the mirror copy must be made bootable

       bosboot -a -l /dev/hd5 -d /dev/hdiskx
       bosboot -a -l /dev/hd5 -d /dev/hdisky
       bootlist -m normal hdisky hdiskx
       

4. Switch off the disk quorum for the volume group.

     smit -C
     System Storage Management - Volume Groups - Set Characteristics ... - Change a Volume Group
     

   selection list via F4 key. Fill the following entries (example for tkrvg) and submit.

     * VOLUME GROUP name                                   tkrvg
     * Activate volume group AUTOMATICALLY                 yes                     +
         at system restart?
     * A QUORUM of disks required to keep the volume       no                      +
        group on-line ?
     

5. Ensure synchronization of mirror and original, e.g.:

     syncvg -v rootvg
     syncvg -v  tkrvg