Understand the Structure of LVM

Here, from this image, you will understand fastly. 

Now, Logically You Can Think Whenever You Wants to Extend the Size of the LV then You can add more size from the volume group and If the VG space is exhausted then add more HDD/EBS then create the PV of its then add those PV to VG so, that VG expands its size.

Steps to Add new disk space to Linux server using VMWare/VirtualBox

• Goto -> Settings-> Storage

• Click to Add Hard disk

• Find the newly added hard disks. You can able to find the newly inserted disk by these commands.

$fdisk -l (List Partitions/Disks)

$lsblk

Let’s Say we hosted the DataBase on our Server Initially with 500GB given space and as we know  Database should run 24/7 because the user’s using it. One day it consumes space about 400GB only 100GB left Now we want to Increase the Space at the runtime only and In the case of static partitioning we need to restart the server but If we restart the server then our database goes down. So, here the role of the LVM concept comes into play. If you have noticed normally all the Linux flavor OS (except some lightweight) uses the LVM concept for the root folder also so that we are able to increase storage in online mode only.