You need to change the location of the Data Loss Prevention (DLP) localhost log.
As of DLP 15.5 the localhost log is controlled in the ManagerLogging.properties file.
Windows:
DLP 15.X - \Program Files\Symantec\DataLossPrevention\EnforceServer\15.X\Protect\config\ManagerLogging.properties
DLP 16.X - \Program Files\Symantec\DataLossPrevention\EnforceServer\16.X\Protect\config\ManagerLogging.properties
Linux:
DLP 15.X - /opt/Symantec/DataLossPrevention/EnforceServer/15.X/Protect/config/ManagerLogging.properties
DLP 16.X - /opt/Symantec/DataLossPrevention/EnforceServer/16.X/Protect/config/ManagerLogging.properties
The line to modify is:
-------------------------------------------------------------------------
In DLP 15.1 and prior versions, the localhost log location is specified in the log4j.properties file.
../SymantecDLP/Protect/tomcat/lib/log4j.properties
The line is:
log4j.appender.R.Directory=