Logical Volume Manager (LVM) is an advanced disk management method. Read the initial sections of the LVM HowTo for a better understanding:
http://www.ibiblio.org/pub/Linux/doc...LVM-HOWTO.html
A volume group is not a filesystem, but is an LVM organizational unit analogous to a traditional extended partition. A volume group can be divided into one or more logical volumes, analogous to how an extended partition can be divided into one or more logical partitions. You can create filesystems in logical volumes and use them much like you would use filesystems in traditional partitions.
A volume group might be formed from one partition, from several partitions on one or more disks or from one or more raid devices. This flexibility combined with the ability to grow and shrink volume groups and logical volumes can greatly simplify disk management once you understand how LVM works and how to administer it.
