SGA exceeds 2GB on Linux 32bit

1. edit init.ora

use_indirect_data_buffers=true 
db_block_size=8192 
db_block_buffers=1048576 # 8Gb
shared_pool_size=1415577600 #2831155200 - 2G

2. shmmax

- check shmmax

# cat /proc/sys/kernel/shmmax
2147483648

- edit  file /etc/sysctl.conf

kernel.shmmax= 4294967295 

# /sbin/sysctl -p

3. mount the ramfs filesystem

# umount /dev/shm 
# mount -t ramfs ramfs /dev/shm 
# chown oracle:dba /dev/shm

4. restart DB