I have a server in my home that we use for storing music we (legally) rip from our CDs as well as various things we download from Youtube or GoogleVideo, etc. It also has a full webserver that has both Drupal and MediaWiki installed on it for us to use to take notes and things...I use this mainly when I am on my machine in the shop doing research to organize it so when I am on the computer in my office I can access it still.

Anyway, when I built it I partitioned it's hard drive with a small /boot partition and the rest in an LVM. My intention was when I ran out of space on that drive I would be able to add another one and just extend the filesystem to increase it's size. This is the main attraction for LVM; Dynamic resizing of a filesystem.

Here are some of the more important terms used by the LVM tools:

Physical Volumes
Physical Extents
Logical Volumes
Logical Extents

(to be continued)