UPDATE OCS INVENTORY 2.0.5 SERVER

Good morning, how are you.
possou the 2.0.5 version Server
and 2.0.5 to ocs agent windows and linux .
How do To update the server and NOT lose as MORE than 200 inventoried machines.
OS agents will be necessary to upgrade?
The version of continuarar agent sending the updated server?
I have problems with SNMP and therefore need to update the OCS .
Thank you.

OPERATING SYSTEM DEBIAN 8.5