Hello,
Keep in mind this has to be on the same controller,
Take a snapshot of your vol0
Make a new volume with the root volume size requirements called "vol00" in the aggregate you wish to move the root volume.
1. You will use the ndmpcopy command to migrate your root volume to the target aggregate. Ensure that NDMP is configured correctly by entering the following commands:
> options ndmpd.enable on
> options ndmpd.authtype challenge
2. Migrate the data by entering the following command at the storage system prompt:
> ndmpcopy /vol/vol0 /vol/vol00
3. set vol00 as the root volume
> vol options vol00 root
4. reboot
5. offline vol0 and rename vol00
> vol rename vol00 vol0
> vol offline vol0
Let me know if you have any questions!