During database upgrade, you have wrongly defined the fenced user which is different with the database instance owner.
./db2iupgrade -u db2def db2abc
As described in KBA 2815623, the fenced user should be the same with the owner of database instance in a SAP system.
Therefore, you need to change it accordingly.
SAP on IBM Db2 for Linux, UNIX, and Windows
fenced user, change, db2iupdt , KBA , BC-DB-DB6-UPG , Upgrade SAP System , BC-DB-DB6 , DB2 Universal Database for Unix / NT , How To
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