Suppose you need more disk capacity on a virtual machine in your environment. You choose the VM in Prism, click ‘update’, select to edit the appropriate disk, and change the size of the disk from 200 to 300GiB. You click update and see that the task completes successfully, then close the VM update UI. The VM details reflect the increase in disk space, but when you access the VM it appears the capacity of the drive is unchanged!
This is actually expected. There is just a bit more work to be done. The partition will need to be extended following the steps for your VM guest operating system.