asm例項有沒有控制檔案嗎？

http://www.itpub.net/showthread.php?threadid=822248&pagenumber=

export ORACLE_SID=+ASM1
sqlplus sys as sysdba
SQL*Plus: Release 10.2.0.2.0 - Production on Thu Jul 26 15:44:34 2007
Copyright (c) 1982, 2005, Oracle. All Rights Reserved.
Enter password:
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP and Data Mining options
SQL> show parameter control
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_file_record_keep_time integer 7
control_files string /u01/app/oracle/product/10.2.0
/rac_db/dbs/cntrl+ASM1.dbf
SQL>
但是我檢查這個路徑，這個檔案並不存在。