Postgres not using shared memory

Hi,

I can't seem to get postgresql to use shared memory and performance is
terrrible.

PostgreSQL 7.4.6 on i686-redhat-linux-gnu, compiled by GCC gcc (GCC)
3.2.3 20030502 (Red Hat Linux 3.2.3-42)

$ uname -a
Linux artsdata 2.4.21-20.0.1.ELsmp #1 SMP Wed Nov 24 20:34:01 EST 2004
i686 i686 i386 GNU/Linux

$ free
total used free shared buffers
cached
Mem: 2055336 1614408 440928 0 4240
1488104
-/+ buffers/cache: 122064 1933272
Swap: 2096440 1216 2095224

$ /sbin/sysctl -a | grep shm
...
kernel.shmall = 1073741823
kernel.shmmax = 1073741823
(I had both above 1 larger, and tried cutting it down by one out of
endpoint paranoia. That should be 1GB.)

postgresql.conf:
#shared_buffers = 126976 # 1GB - 32MB (just to leave some below
kernel limit)
shared_buffers = 6000 # testing to get _some_ shared memory

=> select * from pg_settings where name = 'shared_buffers';
name | setting | context | vartype | source
| min_val | max_val
----------------+---------+------------+---------+--------------------+---------+------------
shared_buffers | 6000 | postmaster | integer | configuration file
| 16 | 2147483647
(1 row)

I've see my setting in pg_settings all along, but free never shows me
any shared
memory used.

I've tried shutting down all the other daemons and restarting
postgresql and nothing
changes.

What am I doing wrong here?

Thanks.

Karl <kop(at)meme(dot)com>
Free Software: "You don't pay back, you pay forward."
-- Robert A. Heinlein