FAS and V-Series Storage Systems Discussions
It is possible to convert FAS2040 HA pair to a disk shelf to connect to FAS2520 system?
You can upgrade a storage system in an HA pair to a storage system in an HA pair in another family by replacing thecontrollers and connecting the disk shelvesTo upgrade the original nodes, you must follow certain guidelines and be aware of restrictions that affect the procedureFor more details, refer https://library.netapp.com/ecm/ecm_download_file/ECMP1151387
The question was not how to reuse existing shelves, but how to convert FAS2040 into disk shelf. To my best knowledge it has never been supported for FAS2000, but I cannot find reference (FAQ does not mention it).