Recently, I wanted add some additional space to the root file system of 30GB in one of my virtual machine, and this is how I did that, It might be helpful for someone who is trying to do the same.
2) Create new partition to the newly added device (/dev/sdb).
3) Verify the new Linux LVM partition created on the new disk (/dev/sdb)
4) Check the details of the existing volume group & its name.
5) Create a physical volume on the newly partitioned device (/dev/sdb)
No change seen yet..
6) Extend the volume group with the newly added disk space.
7) We are able to see the physical volume added to the volume group now
8) Extend the logical volume using below command
9) Resize the filesystem with below command.
10) Now, as required our root(/) filesystem size is increased.