In some cases backend node can be in state PARTIAL because file /DB/NODE-<NODE-ID>/allocatedspace inside storage controller is empty , like
/ # cat /DB/NODE-2759660694/allocatedspace
and in /var/log/messages inside storage controller are records like:
May 6 14:25:11 (none) user.info GROUPMON: Thread-3 : Allocated space mismatch - Node 2759660694 - current 0 actual 78012208911
The issue can be fixed in following way.
Inside storage controller :
1. kill all groupmon processes (before killing them check args with which groupmon is started)
2. delete file /DB/NODE-<NODE-ID>/allocatedspace
3. start groupmon
Mentioned above steps where checked for onapp-store-install-3.1.3-6.noarch , after steps are done backend node should become in state ACTIVE.