idle> startup
ASM instance started

Total System Global Area   83886080 bytes
Fixed Size                  1217836 bytes
Variable Size              57502420 bytes
ASM Cache                  25165824 bytes
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DATA"
idle> select group_number,name,state,total_mb,free_mb from v$asm_diskgroup;

GROUP_NUMBER NAME       STATE                               TOTAL_MB    FREE_MB
------------ ---------- --------------------------------- ---------- ----------
           0 DATA       DISMOUNTED                                 0          0
           2 WATER      MOUNTED                                 2744        599

idle> alter diskgroup data mount;
alter diskgroup data mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DATA"


idle> drop diskgroup data;
drop diskgroup data
*
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15001: diskgroup "DATA" does not exist or is not mounted


idle> drop diskgroup data including contents;
drop diskgroup data including contents
*
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15001: diskgroup "DATA" does not exist or is not mounted

    查询错误信息：

[oracle@localhost ~]$ oerr ora 15063
15063, 00000, "ASM discovered an insufficient number of disks for diskgroup \"%s\""
// *Cause:  ASM was unable to find a sufficient number of disks belonging to the
//          diskgroup to continue the operation.
// *Action: Check that the disks in the diskgroup are present and functioning, 
//          that the owner of the ORACLE binary has read/write permission to 
//          the disks, and that the ASM_DISKSTRING initialization parameter 
//          has been set correctly.  Verify that ASM discovers the appropriate 
//          disks by querying V$ASM_DISK from the ASM instance.

    处理步骤：

         ① /etc/init.d/init.cssd stop
         ② /etc/init.d/init.cssd start
         ③ sleep 90
         ④ restart ASM instance and shutdown immediate
         ⑤ again restart ASM instance

idle> startup
ASM instance started

Total System Global Area   83886080 bytes
Fixed Size                  1217836 bytes
Variable Size              57502420 bytes
ASM Cache                  25165824 bytes
ASM diskgroups mounted

    现在没抛出错误了，不过：

SQL> drop diskgroup data;
drop diskgroup data
*
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15001: diskgroup "DATA" does not exist or is not mounted

    由于10g中还没有drop diskgroup force的语法，所以这里我们借助linux的dd和dbca配合来强制删除这个老顽固。

    步骤：

        ㈠ 通过查询可知raw5挂在了data身上：

[root@localhost ~]# dd if=/dev/zero of=/dev/raw/raw5 bs=1024 count=5
5+0 records in
5+0 records out
5120 bytes (5.1 kB) copied, 0.011998 seconds, 427 kB/s

        ㈡ 在dbca ---> show all ---> 选中raw5