非DBA用户直接登录数据库报错ORA-15081，而使用@连接字符串登录却没有问题

1，非DBA用户直接登录数据库报错ORA-15081，而使用@连接字符串登录却没有问题
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
SQL> select * from v$database;
select * from v$database
*
ERROR at line 1:
ORA-00204: error in reading (block 1, # blocks 1) of control file
ORA-00202: control file: '+CTL1CBDB/cbdb/control01.ctl'
ORA-15081: failed to submit an I/O operation to a disk

2，观察alert日志，发现应该是权限方面的问题
ORA-15025: could not open disk "/dev/rhdiskpower6"
ORA-27041: unable to open file
IBM AIX RISC System/6000 Error: 13: Permission denied
Additional information: 3
Additional information: 4
Additional information: 4227076
kfk_debug_get_user_groups: uid:403, euid:402, gid:404, egid:403
WARNING: failed to open a disk[/dev/rhdiskpower6]
ORA-15025: could not open disk "/dev/rhdiskpower6"
ORA-27041: unable to open file
IBM AIX RISC System/6000 Error: 13: Permission denied

3，磁盘的权限如下，其它用户没有读的权限，用户组是oinstall,而不是asmadmin
[sccbdb1:oracle:/home/oracle] ls -l /dev/rhdiskpower6
crw-rw---- 1 grid oinstall 43, 6 Mar 02 16:25 /dev/rhdiskpower6

4，手工修改权限，问题解决
[sccbdb1:oracle:/dev] ls -l /dev/rhdiskpower6
crw-rw-r-- 1 grid oinstall 41, 6 Mar 02 16:17 /dev/rhdiskpower6


后续：后续发现比较奇怪的问题，在linux平台上其它用户无读的权限竟然也没有问题？感觉可能是个bug
brw-rw---- 1 grid asmadmin 253, 17 Jun 8 09:13 mpath2p1
brw-rw---- 1 grid asmadmin 253, 24 Jun 8 09:13 mpath4p1
brw-rw---- 1 grid asmadmin 253, 19 Jun 8 09:13 mpath1p1