Hello Mr.Kalyan,
Usually, the DBM server is not started explicitly by the user, rather it is started implicitly (for example) by the tool Database Manager CLI (DBMCLI) when the administrative DBM command is called. For example (dbm_*)
All the messages of the DBM server are contained in the log dbm.prt in the work directory (run directory). Error messages of the DBM server are also logged in the file dbmsrv_<computer_name>.err that is stored in the directory above the work directory (run directory) in the directory <GlobalDataPath>/wrk.
If you are a SAP customer - Refer to the Note: 1694323 - FAQ: SAP MaxDB remote SQL server and DBM server.
Regards,Yashwanth