1. To see your current memory usage:

   prstat -Z -s cpu

2. For more ways to check memory usage, see checking memory usage.
3. For more useful commands, see the shell cheat-sheet.

This information needs to be cleaned up and pulled into the wiki ... for now here are some articles to look through:

1. Joyent forum post on apache memory
2. lamp tuning
3. Tuning maxclients
4. Optomizing Apache and MySQL for low memory

1. Listen on the specific IP
   1. Good:

      Listen 1.2.3.4:80

      Listen 1.2.3.4:443

   2. Bad:

      Listen *

      Listen *:80

      Listen *:443

2. Virtualhost entries
   1. Good:

      <VirtualHost 1.2.3.4:80>

      <VirtualHost 1.2.3.4:443>

   2. Bad:

      <VirtualHost *:80>

      <VirtualHost *:443>

How to reduce the memory footprint of your rails app

Webmin can optionally be configured to use much less memory (~10MB continuously, and ~50MB peak during complex operations). Edit /etc/webmin/miniserv.conf and comment out the preload= line. This makes Webmin slower on systems that have plenty of memory, but it makes it use a lot less memory most of the time (with all of the normal preload stuff in a complete Virtualmin system it is about 80-90MB continuous with peaks of 110-120MB during complex operations).

preload is a precaching mechanism for some commonly used libraries, primarily used for Virtualmin related modules.

This is a hard one to really give a step by step on. Only you know what you are using in your stack. The best way to see is to use

svcs -a

and see what is what on your machine and start picking through the items. To remove one thing you use

 svcadm disable <SOMETHING>

so for example if you are using PostgreSQL and not MySQL then to remove MySQL from memory you would do this:

svcsadm disable cswmysql5