使用dbca建库时遇到ORA-01501: CREATE DATABASE failed这个错误，检查告警日志，发现有下面错误信息：
SMON: enabling tx recovery
Fri Apr 29 14:06:25 HKT 2016
replication_dependency_tracking turned off (no async multimaster replication found)
Starting background process QMNC
Process QMNC died, see its trace file
Fri Apr 29 14:06:26 HKT 2016
Errors in file /u01/app/oracle/admin/EPPS/udump/epps_ora_6832.trc:
ORA-00444: background process "QMNC" failed while starting
ORA-00020: maximum number of processes () exceeded
Fri Apr 29 14:06:26 HKT 2016
Errors in file /u01/app/oracle/admin/EPPS/udump/epps_ora_6832.trc:
ORA-01501: CREATE DATABASE failed
ORA-00450: background process 'QMNC' did not start
ORA-00444: background process "QMNC" failed while starting
ORA-00020: maximum number of processes () exceeded
Error 450 happened during db open, shutting down database
USER: terminating instance due to error 450
Instance terminated by USER, pid = 6832
ORA-1092 signalled during: CREATE DATABASE "EPPS"