Advanced Linux capabilities

Memory subsystem

Memory hotplug

You would thought that memory hot plugging is such an esoteric feature you'll never need! But think again! You don't have to have an expensive server with hot plugging hardware, you can as well have virtual machine that you didn't allocate enough memory. In that case you can use hot plugging. Here are links on some documentation I managed to find while searching how exactly to use this feature:

Linux: Documenting Memory Hotplug
vSphere ESX4: Hot Add Memory for Linux Guests
Hot add memory to vMA or other supported Linux guestOSes using vSphere ESX(i) 4.0

Linux filesystems overview

On File Systems
More Linux File Systems
To SSD or not to SSD?
pNFS and the Future of File Systems