Server Memory Usage (Mongrel)


I’m wondering about the memory usage on my rootserver and have some
basic questions.

free -m:
total used free shared buffers
Mem: 1003 928 75 0 311
-/+ buffers/cache: 540 462
Swap: 2047 0 2047

So I have a total of 1003m, with 540m currently used.
I’m running 2 mongrel servers, nginx and postgres which shouldn’t be
very much.

top reports (RES column)
2 mongrels, each around 60 mb (somehow htop reports somehow 4
mongrels, but as I read this is a different story)
1 postmaster process (postgres) around 10mb
and a couple of smaller processes.

If I sum up the RES column in htop, its around 180m

Munin report for the memory usage (curr)
apps: 145m

My question:
I don’t fully understand that, I thought the free -m value of 540m is
the actually used memory? But this seems way too high to me, 50%
actually used.

Can anyone please give some explanations?

using ps aux | grep mongrel will give you an idea (in a percentage)
of what your mongrels’ are weighing in at.
the more you’re loading into the env, the heavier they will be.

rails stack for a hello world app with a few frameworks disabled is
around 60mb.
so thats your baseline.