Solution : https://service.sap.com/sap/support/notes/61915 (SAP Service marketplace login required)
Key words : 
post install/upgrade steps start, post install/upgrade steps, <sid>ofr      rstobj obj, terms post installation upgrade, post-upgrade steps, post processing steps, post processing completed, 3-character system id, cd directory '/qopt', local cd drive
Related Notes : 
       
| 111085 | AS/400: Installation of 3.0F on V4R2 or higher | 
| 82601 | AS/400: Installing 3.0F on OS/400 V4R1M0 | 
| 71474 | AS/400: no syslog / SQL trace is available | 
| 68259 | AS/400: OS/400-relevant changes from V3R7M0 | 
| 64812 | Additional Info: Upgrading to 3.0F DB2/400 |