Here are the steps that I follow when increasing the size of the disk:
01. Turn off the virtual machine.
02. Back up the virtual machine.
03. Extended the disk using web GUI.
04. Boot the VM using Ubuntu Desktop install ISO and select try ubuntu.
05. Launch Gparted.
06. Right Click on both sd2 and sd5 and chose "Deactivate".
07. Resize the extended (sda2) partition.
08. Resized the LVM (sda5) partition.
09. Boot up the VM.
10. Execute the following Commands:
a. lvextend -l +100%FREE [mount point]
example: /dev/vrtemlsrv-vg/root
b. resize2fs [mount point]
example: /dev/vrtemlsrv-vg/root
11. Restart and confirm updated drive size.