ORA-01157 and ORA-01110

SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: '/u01/oradata/orcl/system01.dbf'

it seems NFS storage lock on the mount point.

- Shut down the database
- run the following as root user.

service nfslock status

service nfslock stop


service nfslock start

- start the database.