Oracle Database Discussions

Hi,

I have question about ipcs -a command on Red Hat Enterprise Linux Server release 5.5 (Tikanga).
I have two nodes with sam version of OS (Red Hat Enterprise Linux Server release 5.5 (Tikanga)).

1) First node
Oracle 10gR2 (10.2.0.5)

2) Second node
Oracle 11gR2 (11.2.0.1)

I have started instances on both nodes, and I have typed the command ipcs -a.

On the first node I have seen regular memory allocation record like this.


SQL> show sga

Total System Global Area *285212672* bytes
Fixed Size 1273276 bytes
Variable Size 176161348 bytes
Database Buffers 104857600 bytes
Redo Buffers 2920448 bytes
SQL> !ipcs -a

------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 1933313 root 644 52 2
0x00000000 1966083 root 644 16384 2
0x00000000 1998852 root 644 268 2
0xda4276d4 2392079 oracle 640 *287309824* 16

------ Semaphore Arrays --------
key semid owner perms nsems
0xae3af024 131073 oracle 640 154

------ Message Queues --------
key msqid owner perms used-bytes messages


On the second node I do the same, but>


SQL> show sga

Total System Global Area *1071333376* bytes
Fixed Size 1341312 bytes
Variable Size 763365504 bytes
Database Buffers 301989888 bytes
Redo Buffers 4636672 bytes
SQL> !ipcs -a

------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 2064385 root 644 52 2
0x00000000 2097155 root 644 16384 2
0x00000000 2129924 root 644 268 2
0xf51b80a8 2424838 oracle 660 *4096* 0

------ Semaphore Arrays --------
key semid owner perms nsems
0x7d144704 524289 oracle 660 154

------ Message Queues --------
key msqid owner perms used-bytes messages


Can anybody could me explain this situation.
How to see from OS on 11gr2 how much memory is allocated for SGA?

Thanks!