semi-n00b here. I'm setting up a server that will have Ubuntu 8.04 LTS with a LAMP setup. The system is dual Opteron 248s with 4GB memory.
I had a few questions about settings in the bios:
Will turning off (disable) some of the hardware from bios free up memory for the OS? So disabling the USB Host Controller, serial/parallel ports, floppy disk controller, pci device slots, etc.
I have a setting for "CPU0,CPU1 Link Tx Speed" with option for 800MHz or 1GHz and "CPU0, GOLEM0 Link Tx Speed" with option for 600MHz or 800MHz. Should these be set to the highest settings? Or, how do I consider what these should be set at.
I have a setting for "4GB Memory Hole Adjust" Auto or Manual. It is currently set to Auto but if I set it to Manual I can choose the "Memory Hole Size". I assume this is for the amount of memory set aside for the hardware. Should this be adjusted? But also it leads to my next question...
I am still undecided on 64bit or 32bit OS. If I upgrade to 8GB I will definitely go with 64bit. But with 4GB at the moment and just a vanilla 32bit ubuntu-server installed, the 'free' command shows: Memory: 4090732 (total), 42272 (used), 4048460 (free)
Swap: 4803392, 0, 4803392
Does this mean the OS is getting access to nearly the full 4GB of memory? Also, with 4GB memory, will 64bit give me improvement in performance vs 32bit for a server hosting the full LAMP stack? And what about if I migrate MySQL off to its own dedicated server?
My other machine is dual Athlon MPs with 2GB memory, so 32bit. How do you recommend I use these 2 servers (for best performance) that are hosting a couple of my own sites all on LAMP setups. Do I put MySQL on its own machine, or what do you recommend. I have ecommerce sites as well as a social network type site with photo uploads and some GD processing going on with php.
Thanks and sorry for so many questions.