Is the squeaking from my mouse?

My hard disk has started making occasional squeaky scraping noises – like the sound of a DVD drive ejecting, except my Mac mini doesn’t have a DVD drive. Is this something to worry about? It also coincides with the appearance of the dreaded beach ball. Rav Sinha Squeaky scraping noises are never good. The best case scenario is a fan with a worn bearing. The worst case is a failing hard disk and the worst case is also the most likely. The usual advice is to back up immediately and brace for impact. But this is like waiting until your car hits a patch of ice before putting on your seat belt. You should be – everyone should be – backing up with Time Machine every hour. If you haven’t enabled Time Machine, this advice may come too late. If you are backed up, simply get a replacement hard disk of the same physical dimensions; 2.5 inches by 9.5mm tall (yes, it’s ridiculous that metric and imperial units are mixed like this). To speed up your mini, upgrade to a solid-state drive (SSD); see uk.crucial.com for those. Replace the drive; it will boot into internet recovery mode; download Yosemite, then restore from your Time Machine backup and the scraping noise will be silenced.