NewLogicalDeviceHandler creates a new LogicalDeviceHandler using the specified commander and paths that should be used in place of /dev and /sys directories (empty string to use /dev and /sys, respectively).

VirtletLogicalDevicePrefix denotes the required prefix for the virtual block devices created by Virtlet.

LogicalDeviceHandler makes it possible to store metadata in the first sector of a block device, making the rest of the device available as another logical device managed by the device mapper.