I had stuck idea from developing Uipath RPA to get disk storage value from remote computers.
from server computers i run RPA and the RPA will collect all disk storage information (disk size, free size) and store in datatable.
This activity will be used for monitoring free storage from other computers daily basis.
you have to use WMI objects in power script to get the disk space information from remote machines and use invoke powershell acitivity to execute the powershell script in uipath to get the output. you can pass your servername and diskname as parameters to the powershell script. please refer the below links.