1. Centralize all sites to a single install of WordPress. It allows for quicker turn around time when I need another wordpress site.
2. Allows me to update all sites at once, as opposed to one site at a time.
3. Allows me to control which plugins would be available per site. Unfortunately there are way too many plugins out there, and this way I can up to keep them under control.
4. Allows me to control the themes available to each of the sites.

One of the easiest things you can do, if your modules are dynamically loaded, is to comment them out. When ever a module is active, it takes up some memory in every instance of Apache that runs. When I get more time, I will give a more thorough analysis as to which modules are safe to disable based on your needs, but for right now I’ll give you some general guidelines of what to look for. If you find that a something doesn’t work when you have disabled a module, turn it back on.

Modules:

Disable the modules you know you don’t use. It’s simple to just comment them out.

• userdir_module: this module supports user’s with a website folder. If you’ve ever seen something like http://www.example.com/~chris/  that’s a userdir. If you have a development environment, this is usefully to leave this on if you use it. If not, disable it.
• cgi_module: this module does the handling for /cgi-bin/. If you still use cgi-bin for any of your scripts, leave it on, otherwise, disable it.
• Any module that starts with proxy. If you use any of the proxy modules, leave them on, other wise disable them.
• There are a number of modules that deal with authentication that you can disable, but there are one or two modules you need in that group because they provide code to some other sections of apache that if you were to disable them, you will notice some issues.
• dav_module and dave_fs_module: Unless you use web dav for editing content on your website, disable them.
• Depending on how you installed apache, it will install modules for specific programming languages like PHP, Perl, Python, and other things. If you don’t need those things, disable it.

I’ve used this methods for years, and have found a great reduction in memory usage. Some cases shaving off 2-5MB per process.

I’ve setup the websites on this box to use wordpress, mysql, php, and apache. When I had just one site, I noticed that my memory usage seemed a bit high. It’s a combination of the default settings for mysql, and the memory requirements for wordpress. Fixing wordpress would take some time and that’s really for another posting, so instead, I decided to attack mysql, since that was the bigger culprit of my memory woes.

I have 256MB of Ram dedicated to my VPS, and with the one site, I was using about 170MB. That seemed excessive. I did some digging online for some information about improving the memory usage for MySQL. Here is what I found.

• If you are not using the berkeley database engine, disable it in your configuration file for mysql. You can do this by adding the entry “skip-bdb” under the [mysqld] section. This will tell mysql to not support this database, and it will not load what it would normally need for it.
• If you are not using the inno database engine, disable it in your configuration file for mysql. You can do this by adding the entry “skip-innodb” under the [mysqld] section. This will tell mysql to not support this database, and it will not load what it would normally need for it.
• Another thing I did was add the entry “skip-networking”. This tells mysql to not open itself up to outside traffic. If you’re running a database soley for the server it’s sitting on, then you don’t need the networking support.
• Below are some other entries I’ve added to optimize the performance for a small environment. This will lower your query size, there by taking up less memory:
  • query_cache_limit = 256K
  • query_cache_size = 4M
  • key_buffer = 1M

When I find the original link I will post it. I was able to drop my memory usage on the box from 170MB to 45MB. When I added two more websites, it went up to 85MB. So far so good.

You can view a link to an uptime monitor provided by WebHostingStuff.com about them.