Dear Lucas,
No, you cannot view the LUN capacity usage on the ISM. However, you can view the LUN capacity usage on an application server.
The operation procedure is as follows:
1. Log in to the Windows application server as administrator.
2. Right-click My Computer on the desktop and choose Manage from the shortcut menu.
The Server Manager dialog box is displayed.
3. Choose Storage > Disk Management from the navigation tree.
In the right part of the dialog box, you can view Capacity and Free Space based on which you can calculate the LUN capacity usage.
Thank you.