I ran into a strange problem trying to increase the size of SGA on my database.

I have a system running 32 bit RHEL4 Enterprise edition. The machine has 8 GB of physical memory on it. The memory settings at the OS level are as follows (output of "ipcs -lm"):

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 4194303
max total shared memory (kbytes) = 13118188
min seg size (bytes) = 1

I tried to modify the "sga_max_size" parameter to resize the SGA.

There are 2 10g databases, 2 different versions (10.1.4 and 10.2.0) running on this machine. I tried to increase the memory setting for the 10.2.0 from 2gb to 3gb and it failed with the following error:

ORA-27102: out of memory
Linux Error: 12: Cannot allocate memory
Additional information: 1
Additional information: 851974

On the 10.1.4 instance, when I tried to increase the memory from 1 gb to 2gb I got a similar error.

What am doing wrong?

Please advice.

Thanks in advance.