LVM is a partitioning scheme designed to be more flexible than normal physical disk partitioning. It allows changes in the size of individual volumes without a reboot, and, in most cases, while the file system on the volume is being actively used. It is the recommended way to deploy Xen domains in production. LVM can create "virtual" disk partitions out of one or more physical hard drives and makes it possible to dynamically group them into a virtual single chunk of storage. You can grow, shrink, or move those partitions from drive to drive. You can even create larger partitions than you could with a single drive.
The main components of LVM are as follows: