Hi Rey, I used as

SQL> alter database create datafile '/mnt/db/oracle/oradata/ISDB/isdata11.dbf'
2 as '/mnt/db/oracle/oradata/ISDB/ishdata10.dbf';
alter database create datafile '/mnt/db/oracle/oradata/ISDB/isdata11.dbf'
*
ERROR at line 1:
ORA-01516: nonexistent log file, datafile, or tempfile
"/mnt/db/oracle/oradata/ISDB/isdata11.dbf"

I have checked status in v$datafile and rechecked the path everything is correct.What to do further?