It will also display “OS” and the version number of that OS. Here, again, you’ll find your hard disk(s) they’re probably named something like MainSSD or MainHD. If you have more than one, continue with the next step:Ĭlick on the Apple icon at the top left of your screen System Preferences > Startup Disk. If you only have one, skip the down to “What is taking up all of my startup disk space?” section. If there is more than one of these hard disk icons that show up on your desktop, it means you’ve got multiple hard disks on your Mac. These are disks on your Mac Catalina OS that you can “startup”, this is because they have operating systems on them. In the window that opens, checkmark the “Hard disks” checkbox.Īfter selecting this box, your desktop should now show the hard disks on your mac, in the form of icon(s), like this:.Click on “Finder” in the menu bar at the top of your screen.Hover on the Dock at the bottom of your screen and open Finder.Short version: Take a look under-the-hood of your Mac.īefore we can see what is taking up space on your startup disk, first we have to find it: What’s Causing “Your Disk Is Almost Full” Alert on Catalina OS? Let’s take a closer look at your disk space to see exactly what is causing your disk to be almost full. So, now that we know what a startup disk is, we need to talk about how to fix it. Or install a second internal hard drive on your Mac.Move files to an external hard drive or cloud storage.To make more space on your startup disk you will need to: So how do you fix your almost full startup disk? The same way you solve the problem of a packed fridge – you need to clear up space, of course. What to do when your disk is almost full? If your startup disk is full and you get a message of warning from your Mac, this is a serious indication that you need to free up storage immediately.

A hard disk should never get beyond 85% capacity (especially a startup disk) as you will experience slowness and errors the further you get above that mark. It’s a lot like why is your fridge full? There is no more space! Your disk is almost full and this is very bad news for any drive. Why your disk is almost full on Catalina OS?

Startup disk full mac