打开ASM文件出错

打开ASM文件出错：
+DZYWDATA/dzywdb/onlinelog/redo1_3 open err:OXA-1000 OCI Error -1 occurred at File api/sql/execute.c:123.
ORA-15056: additional error message
ORA-17503: ksfdopn:DGOpenFile05 Failed to open file +DZYWDATA/dzywdb/onlinelog/redo1_3
ORA-17503: ksfdopn:2 Failed to open file +DZYWDATA/dzywdb/onlinelog/redo1_3
ORA-15064: communication failure with ASM instance
ORA-06512: at "SYS.X$DBMS_DISKGROUP", line 96
ORA-06512: at line 1

Error - OCI_ERROR, No such file or directory

对应的SQL应该是：begin DBMS_DISKGROUP.OPEN(:1, :2, :3, :4, :5, :6, :7); end;

大概的使用模式是这样的：
Using the internal package dbms_diskgroup

declare
 fileType varchar2(50); fileName varchar2(50);
 fileSz number; blkSz number; hdl number; plkSz number;
 data_buf raw(4096);
begin
 fileName := '+TEST1_DATADG1/TEST1/spfiletest1.ora';
 dbms_diskgroup.getfileattr(fileName,fileType,fileSz, blkSz);
 dbms_diskgroup.open(fileName,'r',fileType,blkSz, hdl,plkSz, fileSz);
 dbms_diskgroup.read(hdl,1,blkSz,data_buf);
 dbms_output.put_line(data_buf);
end;
/

目前还没有查找出为什么出现这个问题！
哎，等待详细测试，关键我没办法继续测试了。