【求助】数据库open失败

【求助】小弟最近接触数据库，今天启动时发现数据库open失败 ， 找了很久不知道是什么原因。请各位大侠路过多多帮忙。谢谢
相关信息如下
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数据库版本： ORA 10G R2
主机 HPUNIX
现象： 当startup之后，数据库一直停留在 database mounted状态。一直Open不鸟~。
alter log 文件（节选）如下：
Fri Nov 11 09:31:01 2011
Completed: ALTER DATABASE   MOUNT
Fri Nov 11 09:31:08 2011
ALTER DATABASE OPEN
Fri Nov 11 09:40:32 2011
Errors in file /opt/oracle/oracle1/admin/gminer/bdump/gminer_dbw0_3122.trc:
ORA-00240: control file enqueue held for more than 120 seconds
Fri Nov 11 09:47:18 2011
Errors in file /opt/oracle/oracle1/admin/gminer/bdump/gminer_dbw0_3122.trc:
Fri Nov 11 10:02:53 2011
Errors in file /opt/oracle/oracle1/admin/gminer/udump/gminer_ora_3555.trc:
ORA-00494: enqueue [CF] held for too long (more than 900 seconds) by 'inst 1, osid 3122'
Fri Nov 11 10:02:55 2011
System State dumped to trace file /opt/oracle/oracle1/admin/gminer/udump/gminer_ora_3555.trc
Killing enqueue blocker (pid=3122) on resource CF-00000000-00000000
by killing session 54.1

数据库群：23618606