In 32-bit Linux operating system, Memory utilization limit for oracle database

In 32 bit Linux operating system, the default maximum size of the SGA is 1.7GB. For this SHMMAX value needed lager of 1.7GB .
On a 32-bit Linux operating system, without Physical Address Extension (PAE), the physical memory is divided into a 3GB user space and a 1GB kernel space. It is therefore possible to create a 2.7GB SGA, but you will need make several changes at the Linux operating system level by changing the mapped base. In the case of a 2.7GB SGA, you would want to set the SHMMAX parameter to 3GB.

Maximum value of the SHMMAX parameter is 4GB In 32-bit Linux operating system .