Unfortunately, officially CFT is not supported for entry systems. I have hard time to believe in any technical restrictions; but unless NetApp will be willing to do it, your only solution is to temporary head swap from 2240 to midrange, do CFT to another midrange and head swap back to 2552. May be you can convince NetApp to loan you two HA pairs with shelves ... 🙂
Although your external shelves may not contain the root aggregates or root vols, with CFT you must bring over all aggregates, shelves, and disks. Its those internal disks and the aggrs they are a part of that make the entry level platforms a challenge for CFT.
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