Unable to allocate Large_pool_size in 11g

Question

Hi ,
I am running database version 11.2.0.2 in Linux , I have used AMM (Automatic memory management) for memory organization.
I am getting a frequent ORA-04031 errors where it is unable to allocate the memory for RMAN backup from large_pool_size. So I tried to set the large_pool_size = 20M but not allowing where shared_pool_size has free memory around 230M, What could be the reason?
August 2013 14:22
SQL> select * from (select name,bytes/(1024*1024) from v$sgastat where pool='shared pool' order by bytes desc ) where rownum < 11; 
NAME                       BYTES/(1024*1024)
KGLH0                             522.005989
free memory                       230.318596
SQLA                              36.0669022
ASH buffers                               16
KGLS                              10.2996902
XDBSC                             9.62641144
kglsim object batch               9.62521362
row cache                         7.23767853
KGLHD                             6.11631775
KKSSP                             5.85671234
SQL> alter system set large_pool_size=20M scope=both;
alter system set large_pool_size=20M scope=both
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-04033: Insufficient memory to grow pool
Thanks,
Robin

Answer 1

Arun,
The details are the below:
MIN_SIZE COMPONENT
461373440 shared pool
   4194304 large pool
   4194304 java pool
   4194304 streams pool
  33554432 DEFAULT buffer cache
         0 KEEP buffer cache
         0 RECYCLE buffer cache
         0 DEFAULT 2K buffer cache
         0 DEFAULT 4K buffer cache
         0 DEFAULT 8K buffer cache
         0 DEFAULT 16K buffer cache
  MIN_SIZE COMPONENT
         0 DEFAULT 32K buffer cache
         0 Shared IO Pool
         0 ASM Buffer Cache
Thanks,
Robin