The single instance does use same ORACLE_HOME. My doubt is however why the single instance failed when RAC was still up and running? What can cause LMON process terminated with error?
Does your "single instance" use the same ORACLE_HOME as that of RAC? Then the software is RAC-aware, communicates with clusterware etc. You may use non-RAC home. On unix it is simple - just make a copy of ORACLE_HOME, change the environment (ORACLE_HOME and dependants) and relink oracle executable $ export ORACLE_HOME=new_oracle_home # don't forget other environment variables $ cd $ORACLE_HOME/rdbms/lib $ make -f ins_rdbms.mk ioracle rac_off
LS Cheng: > I have a single instance development database located in node 2 of a > 9i RAC database. (development purpose as well). Recently the non-rac > database had an instance failure showing this error > > error 481 detected in background process > ORA-00481: LMON process terminated with error > ksuitm: waiting for  seconds before killing DIAG > > I understand that error should apply to a RAC database. I am not able > to find out why the database failed. Any lights?