5.6.3.2. Logical Volume Resizing
The feature that most system administrators appreciate about LVM is its ability to easily direct storage where it is needed. In a non-LVM system configuration, running out of space means -- at best -- moving files from the full device to one with available space. Often it can mean actual reconfiguration of your system's mass storage devices; a task that would have to take place after normal business hours.
However, LVM makes it possible to easily increase the size of a logical volume. Assume for a moment that our 200GB storage pool was used to create a 150GB logical volume, with the remaining 50GB held in reserve. If the 150GB logical volume became full, LVM makes it possible to increase its size (say, by 10GB) without any physical reconfiguration. Depending on the operating system environment, it may be possible to do this dynamically or it might require a short amount of downtime to actually perform the resizing.