ORA-01503, ORA-12720 when creating controlfile

# error on RAC database when creating controlfile

CREATE CONTROLFILE REUSE SET DATABASE "T01SBT" RESETLOGS FORCE LOGGING ARCHIVELOG
*
ERROR at line 1:
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode

# solution

alter system set cluster_database=false scope=spfile;