The warning message or a notification about “Mac startup disk almost full” lets you know there’s little space left on the main drive. What does “Your disk is almost full” mean? Mac power users often use external hard drives in addition to the main one, but an average user has only one - the startup disk. Since it’s essentially your main disk drive, your Mac “starts up” from this disk (hence the name).

Simply put, the Mac startup disk is a hard drive containing your operating system and all the apps installed on Mac. Spoiler: Moving files to Trash isn’t going to fix it. In this article, we provide step-by-step instructions on how to avoid the “startup disk full” problem. What makes the situation challenging is that most of these Mac storage gobblers are system files you never actually see.īy keeping the Mac startup disk tidy in the first place, you can avoid numerous issues that hamper performance.

This usually happens if you have too many outdated files, old logs, caches, and apps you no longer use. Running low on storage might cause your Mac to slow down or behave strangely. Once “Your disk is almost full” notification pops up on a screen, it’s time to do some work. Make your Mac fast and secure with CleanMyMac X.

Clean up mac hard drive space