---查询oracle用户的用户组
[root@rhel5 ~]# id oracle
uid=502(oracle) gid=102(oinstall) groups=102(oinstall),103(dba)

---给新建的卷组vg2授权
[root@rhel5 ~]# chown -Rf oracle:oinstall /dev/vg2
[root@rhel5 ~]# chmod -Rf 777 /dev/vg2

---切到oracle
[root@rhel5 ~]# su - oracle
-bash-3.2$ sqlplus '/as sysdba'

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jun 21 10:02:56 2013

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area  313860096 bytes
Fixed Size                  1336232 bytes
Variable Size             159386712 bytes
Database Buffers          146800640 bytes
Redo Buffers                6336512 bytes
Database mounted.
Database opened.

SQL> select file#,name from v$datafile

     FILE# NAME
---------- --------------------------------------------------
         1 /oracle/app/oracle/oradata/zxy/system01.dbf
         2 /oracle/app/oracle/oradata/zxy/sysaux01.dbf
         3 /oracle/app/oracle/oradata/zxy/undotbs01.dbf
         4 /oracle/app/oracle/oradata/zxy/users01.dbf
         5 /oracle/newwisdomone.dbf
         6 /oracle/rawfile
         7 /oracle/rawfile2
         8 /oracle/tbs_mod1.dbf
         9 /oracle/tbs_mod2_newposition.dbf

9 rows selected.

---创建裸设备表空间报权限不足
SQL> create tablespace tbs_top datafile '/dev/vg2/lv2' size 30m;
create tablespace tbs_top datafile '/dev/vg2/lv2' size 30m
*
ERROR at line 1:
ORA-01119: error in creating database file '/dev/vg2/lv2'
ORA-27041: unable to open file
Linux Error: 13: Permission denied
Additional information: 1

---确认卷组vg2的权限与用户组，是正确的
[root@rhel5 ~]# ls -l /dev/vg2
total 0
lrwxrwxrwx 1 oracle oinstall 19 Jun 21 09:59 lv2 -> /dev/mapper/vg2-lv2 ----注意：这里lv2是个链接文件
[root@rhel5 ~]# ls -l /oracle/tbs_mod2_newposition.dbf
-rw-r----- 1 oracle oinstall 26222592 Jun 21 10:03 /oracle/tbs_mod2_newposition.dbf
[root@rhel5 ~]# ls -l /dev/vg2/lv2
lrwxrwxrwx 1 oracle oinstall 19 Jun 21 09:59 /dev/vg2/lv2 -> /dev/mapper/vg2-lv2

----查看lv2链接文件对应的真正文件
[root@rhel5 ~]# ls -l /dev/mapper/vg2-lv2
brw-rw---- 1 root disk 253, 1 Jun 21 09:59 /dev/mapper/vg2-lv2 --可以看到还是root:disk

----给lv2对应的真正文件授权
[root@rhel5 ~]# chown -Rf oracle:oinstall /dev/mapper/vg2-lv2
[root@rhel5 ~]# ls -l /dev/mapper/vg2-lv2
brw-rw---- 1 oracle oinstall 253, 1 Jun 21 09:59 /dev/mapper/vg2-lv2

[root@rhel5 ~]# chmod -Rf 777 /dev/mapper/vg2-lv2
[root@rhel5 ~]# su - oracle
-bash-3.2$ sqlplus '/as sysdba'

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jun 21 10:07:28 2013

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

---创建裸设备表空间成功
SQL> create tablespace tbs_top datafile '/dev/vg2/lv2' size 30m;

Tablespace created.

---为了防止重启主机反复授权直接添加裸设备的链接及真正文件到/etc/profile中
[root@rhel5 ~]# tail -5 /etc/profile
chown -Rf oracle:oinstall /dev/mapper/vg2-lv2
chmod -Rf 777 /dev/mapper/vg2-lv2
chown -Rf oracle:oinstall /dev/vg2
chmod -Rf 777 /dev/vg2

小结:

      1,链接与真正设备文件都要进行授权

      2,上述授权脚本写入到/etc/profile中