4.4.3. Resizing Logical Volumes
lvreducecommand. If the logical volume contains a file system, be sure to reduce the file system first (or use the LVM GUI) so that the logical volume is always at least as large as the file system expects it to be.
lvol1in volume group
vg00by 3 logical extents.
lvreduce -l -3 vg00/lvol1