Excessive VM_OUT_BYTES in AWR reports on Oracle 11g Linux 64

We are having a performance problem at the monent, and one of the things I have noticed in the AWR report is the high number for VM_OUT_BYTES and VM_IM_BYTES:

VM_IN_BYTES 13,820,928
VM_OUT_BYTES 1,589,587,968
PHYSICAL_MEMORY_BYTES 33,666,908,160

and When I query the following:
SQL> select * from V$OSSTAT ;

STAT_NAME VALUE OSSTAT_ID
-------------------------------------------------- ---------------- ----------
COMMENTS CUM
---------------------------------------------------------------- ---
.....
VM_IN_BYTES 2194644201472 1009
Bytes paged in due to virtual memory swapping YES
VM_OUT_BYTES 784534494208 1010
Bytes paged out due to virtual memory swapping YES
...

Can someome tell me what exactly does this mean? and it the performance problem memory? We have 32gb on the server.

Rgds. Sheryl