ORA-19863: device block size 4161536 is larger than max allowed: 1048576

channel ORA_DISK_1: starting datafile backup set restore

channel ORA_DISK_1: specifying datafile(s) to restore from backup set

channel ORA_DISK_1: restoring datafile 00001 to /home/oracle/MYDB/system01.dbf

channel ORA_DISK_1: restoring datafile 00006 to /home/oracle/MYDB/data103.dbf

channel ORA_DISK_1: reading from backup piece /dhome/oracle/backup/MYDB_tab1_full_9ogt567_1_1

RMAN-00571: ===========================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS

RMAN-00571: =============================================

RMAN-03002: failure of restore command at 05/04/2013 07:00:39

ORA-19870: error while restoring backup piece /dhome/oracle/backup/MYDB_tab1_full_9ogt567_1_1

ORA-19863: device block size 4161536 is larger than max allowed: 1048576

Cause :The user specified a device BLKSIZE that is larger than the device BLKSIZE specified during compressed backup.

Solution:

find the value of hidden parameter  "_db_file_direct_io_count" change it to given size

SQL> SELECT a.ksppinm NAME,

  b.ksppstvl VALUE,b.ksppstdf deflt,DECODE

 (a.ksppity, 1,'boolean', 2,'string', 3,'number', 4,'file', a.ksppity) TYPE,a.ksppdesc description

FROM sys.x$ksppi a,sys.x$ksppcv b

WHERE a.indx = b.indx

 AND a.ksppinm LIKE '\_%' ESCAPE '\' and a.ksppinm like '%&name%'

 /

Enter value for name: io_count

old   6: AND a.ksppinm LIKE '\_%' ESCAPE '\' and a.ksppinm like '%&name%'

new   6: AND a.ksppinm LIKE '\_%' ESCAPE '\' and a.ksppinm like '%io_count%'

NAME                VALUE          DEFLT           TYPE                      DESCRIPTION

--------               ------------          ---------             --------               ------------------------

_db_file_direct_io_count  4194304 TRUE      number       Sequential I/O buf size

_hash_multiblock_io_count

SQL>  alter system set "_db_file_direct_io_count"=1048576 scope=both;