 I've put together this quick screencast to show you how you can check what time machine is backed up and also how you might be able to restore an external hard disk backed up with time machine. So if we just go into time machine preferences for a second, so system preferences time machine, I find it quite useful to show time machine in the menu bar so I've got that ticked on and while we're in here if you go into options you can actually take a look at anything that's been excluded. So I've got my external hard disk that I use for my time machine backups excluded from from these backups so that's how you can check what's excluded. Obviously if you want to add any disk or folder you can do so by clicking the plus button here. So in terms of finding out what time machine has actually backed up and how you might restore an external hard disk that you have backed up with time machine then if you click on the finder and then from either from the icon if you put it on the desktop here or going to spotlight search for time machine launch time machine it will do the same thing but if you've got the icon set up here enter time machine and you can see at the moment that it's looking at now so you can see here in terms of the different locations that's the time machine external drive that I use my time machine backups. I've also got some data on another external hard disk and I've also got an SSD external hard disk attached to this iMac as well. But if you then go back to a previous backup you can see that once it's actually it's not backing up the time machine backup hard disk because that's grayed out but you can see it is backing up the data on an external hard disk so if we just click that then if you wanted to restore all of that information to that hard disk it's just a question of then selecting all of the top little folders within that hard disk and clicking the restore button it's probably worth noting that if there's a problem you have to replace the hard disk and using time machine to then recover files on the hard disk that you've replaced you need to make sure it's the same name in order for it to restore files back to that disk anyway I hope that helps