Solution : https://service.sap.com/sap/support/notes/905915 (SAP Service marketplace login required)
Key words : 
touch /var/adm/ifx_loader_domainchgrp informix /var/adm/ifx_loader_domainchmod 660 /var/adm/ifx_loader_domain, <inf10_dvd>\rdbms\nt\i386\informix\iconnect\isscript9, file /var/adm/ifx_loader_domain exists, relevant original sapinst master cds/dvds, \program files\common files\driver\9, ibm informix dynamic server failed, directory /var/adm, succeededreading configuration file '/informix/qi1/, front-end software iconnect, original kernel cds/dvds
Related Notes : 
       
| 1528937 | 6.20/6.40 Patch collection installation: Informix 11.70 | 
| 1013658 | New Informix 11.50 and 10.00.xC7 Jumbo versions | 
| 965035 | 6.20/6.40 Patch Collection Installation: Informix / Win | 
| 965034 | 6.20/6.40 Patch Collection Installation: Informix / UNIX | 
| 921967 | disp+work: dld.sl: Unable to find library './dw_stl.sl'. |