1. 11gR2 RAC 角色分离信息
11gR2中安装oracle 集群件和数据库软件中的一些group进行简单的介绍。
oinstall : 这个group是GI 和RDBMS软件的拥有者。
dba : 这个group是数据库的dba group, 对数据库具有最高权限。
asmdba : 这个group是asm实例的dba group, 可以启动/关闭实例，挂载/卸载asm 磁盘组。
asmadmin: 这个group是asm的管理员group,它包含asmdba的全部权限，同时还可以增加/删除 asm 磁盘，磁盘组等。
2. ASM共享磁盘及orale/grid用户及GI_HOME/RDBMS_HOME bin目录的oracle程序正确权限
------------GI及RDBMS软件安装完成，未DBCA创建数据库时的权限：
[root@bys1 ~]# su - oracle
[oracle@bys1 ~]$ cd $ORACLE_HOME/bin
[oracle@bys1 bin]$ ls -al oracle --RDBMS_HOME的
-rwsr-s--x 1 oracle oinstall 239626665 Nov 9 21:31 oracle
[grid@bys1 ~]$ cd $ORACLE_HOME/bin
[grid@bys1 bin]$ ls -al oracle --GRID_HOME的
-rwsr-s--x 1 grid oinstall 209914471 Nov 9 19:07 oracle
[grid@bys1 bin]$ crsctl query crs activeversion
Oracle Clusterware active version on the cluster is [11.2.0.4.0]
------------DBCA创建数据库后的正确权限示例，
即正常的权限：
[oracle@bys1 bin]$ ls -al oracle
-rwsr-s--x 1 oracle asmadmin 239626665 Nov 9 21:31 oracle
[grid@bys1 ~]$ cd $ORACLE_HOME/bin
[grid@bys1 bin]$ ls -al oracle
-rwsr-s--x 1 grid oinstall 209914471 Nov 9 19:07 oracle
[grid@bys1 bin]$ id oracle
uid=502(oracle) gid=501(oinstall) groups=501(oinstall),502(dba),506(asmdba)
[grid@bys1 bin]$ id grid
uid=501(grid) gid=501(oinstall) groups=501(oinstall),504(asmadmin),506(asmdba),507(asmoper)
3.RAC中常见的因GI/RDBMS HOME中oracle程序权限或者ASM使用的磁盘权限有问题引起的问题汇总：
3.1 sqlplus登陆时报错：ORA-12547: TNS:lost contact
在RAC中常见的还有oracle程序的权限不对，
ORA-12547 Errors
The error ORA-12547 indicates that the communication channel has been broken. It's most often thrown because the other end of the process went away unexpectedly.
参考MOS文档：
Note 1307075.1 Oracle Database Fails to Start with Error ORA-12547
Note 381566.1 connect / as sysdba Fails with Ora-12547 And Tns-12514
ORA-12537 / ORA-12547 or TNS-12518 if Listener (including SCAN Listener) and Database are Owned by Different OS User (文档 ID 1069517.1)
Note 744512.1 Ora-12547: Tns:Lost Contact Creating Database After Clean Installation
导致 Scan VIP 和 Scan Listener（监听程序）出现故障的最常见的 5 个问题 (文档 ID 1602038.1)
3.2 安装完GI与RDBMS软件，未使用DBCA创建数据库。使用手动恢复数据库方法，此时rdmbs_home下oracle程序权限问题引发的错误
RMAN> restore controlfile from '/home/oracle/fulldb_SCTTEST_900418795_84';
Starting restore at 06-JAN-16
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=98 instance=scttest1 device type=DISK
channel ORA_DISK_1: restoring control file
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 01/06/2016 13:20:29
ORA-19870: error while restoring backup piece /home/oracle/fulldb_SCTTEST_900418795_84
ORA-19504: failed to create file "+DATA/scttest/controlfile/control01.ctl"
ORA-17502: ksfdcre:3 Failed to create file +DATA/scttest/controlfile/control01.ctl
ORA-15001: diskgroup "DATA" does not exist or is not mounted
ORA-15055: unable to connect to ASM instance
ORA-01034: ORACLE not available
ORA-27123: unable to attach to shared memory segment
其它类似报错类型：
SQL> create spfile='+DATA/jdedb/spfilejdedb1.ora' from pfile;
create spfile='+DATA/jdedb/spfilejdedb1.ora' from pfile
*
ERROR at line 1:
ORA-17502: ksfdcre:4 Failed to create file +DATA/jdedb/spfilejdedb1.ora
ORA-15001: diskgroup "DATA" does not exist or is not mounted
ORA-15040: diskgroup is incomplete
查看alert日志：
Mon Nov 07 14:12:19 2016
Decreasing number of real time LMS from 2 to 0
Mon Nov 07 14:17:50 2016
ORA-15025: could not open disk "/dev/raw/raw2"
ORA-27041: unable to open file
Linux-x86_64 Error: 13: Permission denied
Additional information: 9
Mon Nov 07 14:17:50 2016
SUCCESS: diskgroup DATA was dismounted
ERROR: diskgroup DATA was not mounted
3.3 ASM使用的磁盘权限问题导致的报错
11.2.0.3中报错信息如下：
ORA-15045:ASM file name '+DATA1' is not in reference form
ORA-17502:ksfdcre:5 Failed to create file +DATA1
ORA-15081:failed to submit an I/0 operation to a disk;
[oracle@bys1 bin]$ ls -al /dev/sdc /dev/sdd --这可以看到只有GRID用户可读写，要修改。
brw-r----- 1 grid asmadmin 8, 32 Apr 11 19:24 /dev/sdc
4.LINUX “suid”和“sgid”权限简介
Linux 权限模型有两个专门的位，叫做“suid”和“sgid”。当设置了一个可执行程序的“suid”这一位时，它将代表可执行文件的所有者运行，而不是代表启动程序的人运行。
关于6751权限的说明：
6751分别指定了ugoa的权限：
第一位6是suid+sgid权限
第二位7代表g（组）有读、写、执行权限
第三位5代表o（其它用户）有读、执行权限
第四位1代表a（所有者、组、其它用户）有执行权限
----------------------------本文内容参考MOS文档：
Oracle Database Fails to Start with Error ORA-12547 (文档 ID 1307075.1)
"Connected to an Idle Instance" Message when Connecting Bequeath to a Running Instance (文档 ID 435044.1)
Troubleshooting when srvctl can't start RAC instance, but sqlplus can start it (文档 ID 844272.1)
10gR2 Database Creation Fails with 11gR2 ASM storage: ORA-15045, ORA-17502, ORA-15081 [ID 1384180.1]
Database Creation on 11.2 Grid Infrastructure with Role Separation ( ORA-15025, KFSG-00312, ORA-15081 ) (文档 ID 1084186.1)
ORA-00600 [kfioTranslateIO03] [17090] (Doc ID 1336846.1)
ORA-15183 Unable to Create Database on Server using 11.2 ASM and Grid Infrastructure (文档 ID 1054033.1)
Startup Instance Failed with ORA-27140 ORA-27300 ORA-27301 ORA-27302 and ORA-27303 on skgpwinit6 (文档 ID 1274030.1)
https://blogs.oracle.com/Database4CN/entry/%E4%BB%BB%E5%8A%A1%E8%A7%92%E8%89%B2%E5%88%86%E7%A6%BB_job_role_separation_%E7%AE%80%E4%BB%8B
