How to simulate block corruption

REM simulate block corruption for test 12.1
RMAN> alter database datafile 6 offline;

Statement processed


dd if=zero.txt of=C:\PROJECT\DB12CDB\DB12CDB\USERS01.DBF seek=30 bs=8192

RMAN> select * from v$database_block_corruption;

no rows selected

RMAN> validate datafile 6;

Starting validate at 10-NOV-15
using channel ORA_DISK_1
channel ORA_DISK_1: starting validation of datafile
channel ORA_DISK_1: specifying datafile(s) for validation
input datafile file number=00006 name=C:\PROJECT\DB12CDB\DB12CDB\USERS01.DBF
channel ORA_DISK_1: validation complete, elapsed time: 00:00:03
List of Datafiles
=================
File Status Marked Corrupt Empty Blocks Blocks Examined High SCN
---- ------ -------------- ------------ --------------- ----------
6    FAILED 0              29           641             1003639
  File Name: C:\PROJECT\DB12CDB\DB12CDB\USERS01.DBF
  Block Type Blocks Failing Blocks Processed
  ---------- -------------- ----------------
  Data       0              15
  Index      0              3
  Other      1              593

validate found one or more corrupt blocks
See trace file C:\APP\ORACLE\diag\rdbms\db12cdb\db12cdb\trace\db12cdb_ora_10992.trc for details
Finished validate at 10-NOV-15

RMAN> select * from v$database_block_corruption;

     FILE#     BLOCK#     BLOCKS CORRUPTION_CHANGE# CORRUPTIO     CON_ID
---------- ---------- ---------- ------------------ --------- ----------
         6         30          1                  0 CORRUPT            0

RMAN> alter database datafile 6 online;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of sql statement command at 11/10/2015 11:14:15
ORA-01113: file 6 needs media recovery
ORA-01110: data file 6: 'C:\PROJECT\DB12CDB\DB12CDB\USERS01.DBF'

RMAN> recover corruption list;

Starting recover at 10-NOV-15
using channel ORA_DISK_1

channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00006
channel ORA_DISK_1: reading from backup piece C:\APP\ORACLE\FAST_RECOVERY_AREA\DB12CDB\BACKUPSET\2015_11_10\O1_MF_NNNDF_TAG20151110T101009_C43JQCC6_.BKP
channel ORA_DISK_1: piece handle=C:\APP\ORACLE\FAST_RECOVERY_AREA\DB12CDB\BACKUPSET\2015_11_10\O1_MF_NNNDF_TAG20151110T101009_C43JQCC6_.BKP tag=TAG20151110T101009
channel ORA_DISK_1: restored block(s) from backup piece 1
channel ORA_DISK_1: block restore complete, elapsed time: 00:00:01

starting media recovery
media recovery complete, elapsed time: 00:00:01

Finished recover at 10-NOV-15

RMAN> alter database datafile 6 online;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of sql statement command at 11/10/2015 11:14:32
ORA-01113: file 6 needs media recovery
ORA-01110: data file 6: 'C:\PROJECT\DB12CDB\DB12CDB\USERS01.DBF'

RMAN> recover datafile 6;

Starting recover at 10-NOV-15
using channel ORA_DISK_1

starting media recovery
media recovery complete, elapsed time: 00:00:00

Finished recover at 10-NOV-15

RMAN> alter database datafile 6 online;

Statement processed