I was looking over your page because 3013 total memory but I’m only using little more than half of it, or 1615. I was wondering how to increase the amount, because I’m having difficulty making sure the PAE kernel has first priority and then changing the default line to 0- or if this is even the right process to accomplish this. My current PAE kernel version is 2.6.38-11-generic-pae.

Thanks for helping a complete novice out!

Sounds to me like you have the right kernel installed with the PAE extension.

How much “physical” RAM do you have installed?

This documentation isn’t for using up your available RAM, but to allow 32-bit OS’s to see more than the usual 32-bit limit ~4GB…, ala 64-bit.

Even though Linux likes to use all available RAM with the current load, and should free up RAM… practice would show that having some free RAM available does allow for spikes in traffic, auto updates, backups etc.

The last thing you want to do is end up in Swap where the HDD is used as RAM when Real RAM has been exhausted, and the server ends up thrashing about; services would slow to a crawl.

It’s nice to have some headroom (free ram).