Logical Volume Manager (LVM) is a software-based RAID-like system that lets you create “pools” of storage and add hard drive space to those pools as needed. There are lots of reasons to use it, especially in a data center or any place where storage requirements change over time. Many Linux distributions use it by default for desktop installations, though, because users find the flexibility convenient and there are some built-in encryption features that the LVM structure simplifies.
However, if you aren’t used to seeing an LVM volume when booting off of a Live CD for data rescue or migration purposes, LVM can be confusing because the mountcommand can’t mount LVM volumes. For that, you need LVM tools installed. The chances are great that your distribution has LVM utils available—if they aren’t already installed.
This tutorial explains how to create and deal with LVM volumes.
Read more at OpenSource.com