Solution : https://service.sap.com/sap/support/notes/1522123 (SAP Service marketplace login required)
Key words : 
/usr/sap/p16/mds00/config/mds, platform-specific administrative utility tools, prior mdm versions running, open client/server connections, terms mds reason, open dbms connections, mds log files, os default values, hp-ux systems, file-max parameter
Related Notes : 
       
| 1577797 | MDM with LDAP on HP-UX crashes due to excessive memory usage | 
| 1541213 | Resource limits on UNIX systems (ulimit) | 
| 1472180 | MDM prerequisites and runtime recommendations on HP-UX |