oracle asm磁盘空间使用情况不正确

--alert 提示db_recovery_file_dest_size 空间不足，无法正常归档Sat Apr 22 00:32:14 2017
Errors in file /u01/app/oracle/diag/rdbms/sdmddb/SDMDDB1/trace/SDMDDB1_m000_82504.trc:
ORA-19815: WARNING: db_recovery_file_dest_size of 1471152128000 bytes is 97.18% used, and has 41450209280 remaining bytes available.
************************************************************************
You have following choices to free up space from recovery area:
1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard,
   then consider changing RMAN ARCHIVELOG DELETION POLICY.
2. Back up files to tertiary device such as tape using RMAN
   BACKUP RECOVERY AREA command.
3. Add disk space and increase db_recovery_file_dest_size parameter to
   reflect the new space.
4. Delete unnecessary files using RMAN DELETE command. If an operating
   system command was used to delete files, then use RMAN CROSSCHECK and
   DELETE EXPIRED commands.
************************************************************************查看归档
SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     82272
Next log sequence to archive   82274
Current log sequence           82274
SQL> 
SQL> 
SQL> show parameter recoverNAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest                string      +ARCH
db_recovery_file_dest_size           big integer 1403000M
db_unrecoverable_scn_tracking        boolean     TRUE
recovery_parallelism                 integer     0
可以看出归档使用的是+ARCH磁盘组，配额了大概1.4T查看V$FLASH_RECOVERY_AREA_USAGE;，发现使用率都加一块很低啊，空间剩余很多
FILE_TYPE            PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE
-------------------- ------------------ -------------------------
NUMBER_OF_FILES
---------------
CONTROL FILE                          0                         0
              1REDO LOG                            .33                         0
              9ARCHIVED LOG                        .26                         0
             18BACKUP PIECE                      36.79                         0
             51IMAGE COPY                            0                         0
              0FLASHBACK LOG                       .18                       .11
              5FOREIGN ARCHIVED LOG                  0                         0
              0查看v$recovery_file_dest;发现SPACE_USED使用情况完全和V$FLASH_RECOVERY_AREA_USAGE;不一样，总文件数也不一样
SQL>  select substr(name,1,30),SPACE_LIMIT/1024/1024/1024,SPACE_USED/1024/1024/1024,SPACE_RECLAIMABLE/1024/1024/1024,NUMBER_OF_FILES
  2  from v$recovery_file_dest;SUBSTR(NAME,1,30)
------------------------------------------------------------
SPACE_LIMIT/1024/1024/1024 SPACE_USED/1024/1024/1024
-------------------------- -------------------------
SPACE_RECLAIMABLE/1024/1024/1024 NUMBER_OF_FILES
-------------------------------- ---------------
+ARCH
                1370.11719                1137.01855
                      1.50292969            3210
查看asm磁盘组使用情况ASMCMD> lsdg
State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name
MOUNTED  EXTERN  N         512   4096  1048576   1433597   863617                0          863617              0             N  ARCH/
MOUNTED  NORMAL  N         512   4096  1048576      3069     2017             1023             497              0             Y  CRS/
MOUNTED  EXTERN  N         512   4096  1048576   1126393   209072                0          209072              0             N  DATA/ASMCMD> cd arch
ASMCMD> 
SDMDDB/
ASMCMD> du
Used_MB      Mirror_used_MB
 569803              569803