We recently got a question about rebuilding LDoms:
"Is there a way to use the metadata to rebuild an LDom on another CDom, if Ops Center was down or couldn't do Automatic Recovery?"
Yep. Beginning in 12.3.1, when you shut down and detach an LDom, the guest constraints are saved in an xml file in the /var/opt/sun/xvm/guests/ directory on the CDom. You can use this file to manually reconstruct the guest if
necessary.
The xml file is named according to the guest name. For
example, if you shut down and detach a guest named guest_1, the guest
constraints are saved in the /var/opt/sun/xvm/guests/guest_1.xml file.
The Manage Logical Domains section of the docs discusses this, as well as a number of other options for managing LDoms.