Linux noob here. I have a 256MB VPS on Ubuntu 11.04 server and when I run "free -m" the result shows all memory being used (including the second line re: buffers/cache). I found this very strange, considering I only have 5 Apache processes running each chewing up about 20MB each. MYSQL is taking up 30MB. To my knowledge, and according to "top", I have no other memory hogs operating.

Settings that may be relevant:

PHP memory_limit = 32M
MYSQL key_buffer = 16M
Prefork MPM Maxclients = 10

So when I reviewed these settings, I naturally thought maxclients was too high, so I tried switching it to 5. Now not only does my memory still show as being 100% used, my website loads much, much slower, despite not getting any traffic aside from mine at the moment. I don't understand this. I thought a single Apache process handles all requests from a client received within the "KeepAliveTimeout" window, which I've set to 2 seconds. With my initial config. of 10 maxclients, my page load times are around .3ms, so a single process should handle that no problem, correct?

So next I went to an extreme level of 1 for maxclients. My memory is still at 100% usage and my site loads painfully slow. I'm a noob at a complete loss here. According to the many tutorials I've read on basic server setup, I should be good to go.

Help! Please!

Edit:
             total       used       free     shared    buffers     cached
Mem:           256        256          0          0          0          0
-/+ buffers/cache:        256          0
Swap:            0          0          0