You need to identify how much space will be needed to perform a DLP upgrade, or execute the upgrade readiness tool.
The following command should be entered at a command prompt (with administrator rights). Enter your own DLP Schema password where it says <DLP Schema password>:
expdp protect/<DLP Schema password>@protect NOLOGFILE=YES ESTIMATE_ONLY=YES schemas=protect EXCLUDE=TABLE:"IN\('MESSAGELOB'\,'MESSAGECOMPONENTLOB'\,'CONDITIONVIOLATIONLOB'\,'AGENTEVENT'\,'SYSTEMEVENT'\,'SYSTEMEVENTPARAMETER'\)"
You can also leave off the username and password to be prompted for these using secure methods.
expdp NOLOGFILE=YES ESTIMATE_ONLY=YES schemas=protect EXCLUDE=TABLE:"IN\('MESSAGELOB'\,'MESSAGECOMPONENTLOB'\,'CONDITIONVIOLATIONLOB'\,'AGENTEVENT'\,'SYSTEMEVENT'\,'SYSTEMEVENTPARAMETER'\)"