It is very easy to extend already created logical volume, if you have free space in volume group. You need to understand the details about existing volume group from which this logical volume created before extending the logical volume. Follow the following steps:
Step1: Check the Name of Volume Group of respective logical Volume. You can see it by two commands, lvs or lvdisplay.
Step2: Check free space in Volume Group.
Step3: You can extend the logical volume with free space present in its own Volume Group(VG). Currently, we have 196MB free space in Volume group of logical volume (MyLogicalVol). We will extend the partition /dev/mapper/MyVolume-MyLogicalVol by 100MB.
Step4: Check the free space of Logical Volume by command df –kh as mentioned above.