Oracle - ORA-01172/ORA-01151 [ Baby does not cry =)]

SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01172: recovery of thread 1 stuck at block 7583 of file 2
ORA-01151: use media recovery to recover block, restore backup if needed


SQL> recover database;
Media recovery complete.
SQL> alter database open;



SQL> select * from dba_data_Files where file_id=2;

FILE_NAME
------------------------------------------------------------------------------------------------------------------------
   FILE_ID TABLESPACE_NAME                     BYTES     BLOCKS STATUS    RELATIVE_FNO AUT   MAXBYTES  MAXBLOCKS
---------- ------------------------------ ---------- ---------- --------- ------------ --- ---------- ----------
INCREMENT_BY USER_BYTES USER_BLOCKS ONLINE_
------------ ---------- ----------- -------
/home/etr/db/dbfiles/undotbs01.dbf
         2 UNDOTBS1                        214958080      26240 AVAILABLE            2 YES 8388608000  1024000
       25600  214892544       26232 ONLINE