Oracle vs OS Memory Utilization

I have a Solaris server V445 running:
5.10 Generic_120011-14 sun4u sparc SUNW,Sun-Fire-V445

The server has 8G of memory. However TOP only is showing 700M available.

The DB instance is only taking up approx 1G in shared memory segment, i.e. SGA

GROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIME DTIME CTIME
Shared Memory:

m          1   0x76125b4  --rw-r-----   oracle      dba   oracle
dba     36  943734784

BY THE WAY ORACLE 10G: Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

SQL> select * from v$SGA;

NAME                      VALUE
-------------------- ----------
Fixed Size              2034632
Variable Size         486544440
Database Buffers      419430400
Redo Buffers           35708928

Why is the server only showing 700M free. I actually brought the instance down due to perf issues today then viewed memory. When instance was down it was showing 7+G of available memory. As soon as I started the instance with no connections the memory immediately dropped to 800M available.

Also before bringing instance down swap utilization was at 50% of available, i.e. 4G out of 8G.

Curent TOP
Memory: 8192M phys mem, 762M free mem, 8193M total swap, 8193M free swap

At least swap is not being used now.

What is eating up all the OS memory?

NOTE: There is another server running 2 9i instances with 8G of mem and 3G in share memory for the 2 instances and this server show 3G free mem.

Thanks. Received on Thu May 08 2008 - 17:05:04 CDT