I often have customers ask if Turbonomic can make recommendations on disk sizing because it is something that comes (essentially) disabled out of the box. Good news is it is pretty easy to turn on the functionality. All you will need to do is go to Policy > Analysis > Resize Recommendation Increment Constraints and modify the vStorage increment from the default 99999 GB to something more manageable like 10 or 15 GB.
After the recommendations have been turned on you will start seeing recommendations from Turbonomic to upsize VM drives that need more space.
Today implementation of these actions is recommend only, as you will need to go into the VM OS in order to configure the proper disk. Many customers will push this recommendation out to a configuration manager or CMDB in order to implement the action.