[varispeed]

I would be careful with hard drives. As I learned couple of days ago when I got my 10 year old hard drive from storage, I was unable to read most of the data as the drive would start to intermittently disconnect from the computer. Most likely the drive is okay, but the board has developed an issue - maybe capacitors gone bad or something. Now, I am yet to check if it is the one that has hardware encryption (I supposed to get rid of all of them and copy data to alternative drives) - there are drives that encrypt the data by default and if you don't set up the key, the encryption still takes place with some default key. If the board dies for some reason, then you won't ever be able to decrypt the data - even if technically was unencrypted, even by swapping the board from a working hard drive. This happened to me once and I lost 3TB of important data couple of years ago.

That being said - I think the best additional backup is to store important things on BluRay - producers estimate they should last 80-100 years and so far never had a bad disk, even those burned years ago.

[brokenmachine]

I recommend ddrescue for data recovery, worked really well when I needed it.

It will resume when you hook the drive back up, and work around dead sectors.