|I will leave the recovery issues to others.|
But I will say this: You should always have a current backup of important data stored on any media. Hard drives fail, often without warning or apparent reason. And since external drives are sometimes subject to rough treatment they are generally less reliable than internals. Professional recovery of data from a failed drive is very expensive, often $1,000 US or more.
Some people maintain 3 or even more copies of particularly important data and keep them in different locations.