To mirror a root volume group

1. Extend the DMP-enabled rootvg to a second DMP device.

   See Extending an LVM rootvg that is enabled for DMP.

   If the rootvg is already extended over DMP device using the recommended steps, then go to step 2.

2. Create the mirror of the root volume group.

   # mirrorvg rootvg
   0516-1734 mklvcopy: Warning, savebase failed.  Please manually 
   run 'savebase' before rebooting.
   ....
   0516-1804 chvg: The quorum change takes effect immediately.
   0516-1126 mirrorvg: rootvg successfully mirrored, user should 
   					perform bosboot of system to initialize boot records.  
   					Then, user must modify bootlist to include:  hdisk74 hdisk70.

3. As the output of the mirrorvg command indicates, run the savebase command on /dev/ipldevice. If the savebase command returns a non-zero value, then retry the command on the paths of current boot disk (hdisk70, hdisk72) until it succeeds.

   # savebase -d /dev/ipldevice

   # echo $?
   0

4. As the output of the mirrorvg command indicates, run the bosboot command to initialize the boot records. If the bosboot command fails on /dev/ipldevice, then retry the command on the paths of current boot disk until it succeeds.

   # bosboot -ad /dev/ipldevice
   A previous bosdebug command has changed characteristics of this
       boot image.  Use bosdebug -L to display what these changes are.
   
   bosboot: Boot image is 56863 512 byte blocks.

5. Include the paths corresponding to the mirror device in the boot list. In this example, hdisk70 and hdisk72 are the original boot disk. Add the paths for hdisk73 and hdisk74.

   # bootlist -m normal -o
   hdisk70 blv=hd5
   hdisk72 blv=hd5

   # bootlist -m normal hdisk70 hdisk72 hdisk73 hdisk74 blv=hd5

   # bootlist -m normal -o
   hdisk70 blv=hd5
   hdisk72 blv=hd5
   hdisk73 blv=hd5
   hdisk74 blv=hd5

6. Verify the rootvg.

   # lsvg -p rootvg 
   rootvg: 
   PV_NAME     PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION 
   hdisk70     active    39        361     127..05..00..101..128 
   hdisk73     active   639        361     127..05..00..101..128