TNS-12547: TNS:lost contact问题的解决办法！
刚刚安装好的RAC one node 突然连不上数据库了。
检查CRS的状态：
[grid@Linux ~]$ srvctl status database -d ORCL
Database is not running.
[grid@Linux ~]$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora.DATA1.dg ora....up.type ONLINE ONLINE linux
ora....ER.lsnr ora....er.type ONLINE ONLINE linux
ora....R1.lsnr ora....er.type ONLINE UNKNOWN linux
ora.asm ora.asm.type ONLINE ONLINE linux
ora.cssd ora.cssd.type ONLINE ONLINE linux
ora.diskmon ora....on.type ONLINE ONLINE linux
ora.orcl.db ora....se.type ONLINE OFFLINE
ora....rcl.svc ora....ce.type ONLINE OFFLINE
数据库日志报如下错误：
Fatal NI connect error 12547, connecting to:
(DESCRIPTION=(ADDRESS=(PROTOCOL=beq)(PROGRAM=/oracle/app/grid/product/11.2.0/bin/oracle)(ARGV0=oracle+ASM_o001_orcl)(ENVS='ORACLE_HOME=/oracle/app/grid/product/11.2.0,ORACLE_SID=+ASM')(ARGS='(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))'))(enable=setuser)(CONNECT_DATA=(CID=(PROGRAM=oracle@Linux)(HOST=Linux)(USER=oracle))))
VERSION INFORMATION:
TNS for Linux: Version 11.2.0.1.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.1.0 - Production
Time: 16-APR-2012 06:18:20
Tracing not turned on.
Tns error struct:
ns main err code: 12547
TNS-12547: TNS:lost contact
ns secondary err code: 12560
nt main err code: 517
TNS-00517: Lost contact
nt secondary err code: 32
怀疑是权限出了问题，REF：TNS-12518 Can Not Connect To RAC 11gR2 Database [ID 1088754.1]。
以grid用户查看+ASM的权限,发现如下结果：
-rwsr-s--x 1 oracle oinstall 176M Apr 15 07:53 oracle
修改权限：
[grid@Linux bin]$ chown grid:oinstall oracle
chown: changing ownership of `oracle': Operation not permitted
[grid@Linux bin]$ su root
Password:
[root@Linux bin]# chown grid:oinstall oracle
[root@Linux bin]# ls -lrth oracle
-rwxr-x--x 1 grid oinstall 176M Apr 15 07:53 oracle
[root@Linux bin]# chmod 6751 oracle
[root@Linux bin]# ls -lrth oracle
-rwsr-s--x 1 grid oinstall 176M Apr 15 07:53 oracle
[root@Linux bin]# exit
exit
[grid@Linux bin]$ id
uid=501(grid) gid=501(oinstall) groups=501(oinstall),502(dba),503(oper),504(asma
dmin),505(asmoper),506(asmdba)
[grid@Linux bin]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon Apr 16 06:33:28 2012
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size 2220200 bytes
Variable Size 297799512 bytes
Database Buffers 763363328 bytes
Redo Buffers 5554176 bytes
Database mounted.
Database opened.
SQL> SQL> exit
数据库恢复正常！
到底是什么原因导致原来的正常的数据库不正常了，目前还不是很清楚！
[oracle@Linux ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon Apr 16 06:34:02 2012
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size 2220200 bytes
Variable Size 297799512 bytes
Database Buffers 763363328 bytes
Redo Buffers 5554176 bytes
Database mounted.
Database opened.
SQL> SQL> exit