To reduce the size of a logical volume, use the lvreduce command. 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.

The following command reduces the size of logical volume lvol1 in volume group vg00 by 3 logical extents.

lvreduce -l -3 vg00/lvol1