Disk Utility on an older iMac gave a S.M.A.R.T. warning on the internal hard drive. This machine has a Time Machine backup. My preference is to do a file level clone to a new external hard drive of the internal HD before it fails, rather than replace the internal drive. I would then use this new external drive as the startup all the time.

My question is does Time Machine do its back up of the startup drive, regardless of what it may be, or does it only back up the internal drive?


On a Mac since 1984.
Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.