How to check Data disk space and configuration

Hi,
I used the “Move data disk” option to move data to a USB SSD drive, and it seemed to work fine. Now I have a SD card and a USB SSD card connected to my rpi4.
The system is back online, but how do I check if everything is fine and how much space is used on the SSD drive ?

“ha os info” does state that I’m using the Kodak SSD. But “ha os datadisk list” shows empty lists !?
hassio

Thanks @MaxK but that is very generic asnwer to my question. The documentation for “System Monitor” says “One sensor per found disk/mount point will be created”. When I use System Monitor I only see one disk … and it’s showing info regarding the SSD. How can I check the disk usage of the SD Card versus the SSD usb disk ?

there is no issue with the “ha os datadisk list” returnign empty lists ?