Its best to think of the storage cells as inviolate. you do NOTHING on the storage cells. They are re-imaged from scratch after every major version upgrade and anything you do could 1) interfere with this process and 2) not survive the process anyway.
The Exadata storage cell is truly meant to serve as an appliance /black box that you shouldn't ever need to mess about with on your own. ( unless you have a spare Exadata to play with that no one minds if you break too badly and few people have that luxury.)