While working on your MacBook Air, Pro, or Mini, you’ve probably seen the warning “Your startup disk is almost full.” Ever wondered what it means? Well, basically, it means you’re out of space on your startup disk and you need to remove a few things. But what is a startup disk? In this article, we’ll explain it in detail. We’ll also identify the reasons why the above error message may appear and describe different ways to fix the problem.
If you’re more interested in finding a quick solution, you can skip the theoretical part and move straight to the section on how to free up space on Mac’s startup disk.
We also recommend that you download a simple program like Movavi Mac Cleaner to solve the problem quickly and automatically.
A startup disk is a hard drive or partition of a hard drive that contains your computer’s OS X.
Your Mac hard drive can only have one partition (or disk) for all the data stored in the system. More advanced users may have two or more hard drive partitions; in this case, the storage will be divided between the partitions, and the startup disk will be the one with the OS on it.
The message appears if your startup disk has less than 15% free space available, which happens when your hard drive is filled with different files and applications. What you need to do is clear some space on your disk.
But first you should check your Mac’s storage summary to identify the files that can be let go.
The categories Movies, Photos, and Audio will likely take up the biggest chunk of space – you can seek out and delete the files you no longer need. If you want to learn more about cleaning junk from your system, visit our guide on how to free up space on your Mac.
There are a number of ways to make space on your startup disk.
Just go to Finder > Go > Home > File > Find, click the Kind menu, and choose Other. Check the box next to File Size, then enter a size value and locate items that are larger than that value. Select the files you want to compress, control-click them, and choose Compress.
Another alternative is to transfer some of the files to an external hard drive.
Open the Desktop folder and delete all the junk files and icons for the apps you no longer use. This will help your Mac boot faster.
Remember that the system doesn’t automatically delete things you move to the Trash. You have to empty the Trash by hand. To do this, control-click the Trash icon in the Dock and select Empty Trash.
Caches are temporary files used for speeding up certain tasks. Over time, these files often become bloated. Deleting them can free up some serious space.
Open the Finder. Click Go in the menu bar and select Go to Folder. Enter ~/Library/Caches/. Now remove files and folders that are taking up the largest amount of space. You can spare yourself the trouble of handpicking all the cache files – just using Movavi Mac Cleaner is a lot easier. Read more here.
You can also empty your browser cache for a bit more space. Learn more about the procedure here.
Launch the Finder and go to your Photos library. Control-click the library and choose Show Package Contents. Now go through the folders and carefully delete all service copies of your photos.
This is quite tricky because you may accidentally remove wrong or critical files. To do this in a safer and faster way, download Movavi Mac Cleaner.
In a Finder window, open the Go menu. Choose Go to Folder and enter ~/Music/iTunes/Previous iTunes Libraries. Get rid of the libraries you no longer need.
In a Finder window, open the Applications folder. Control-click an application and select Show Package Contents. Go to Contents and open the Resources folder. Locate files ending in “.lproj” – these are language packs. Delete the ones you never use and empty the Trash afterwards.
You can also do it using Movavi Mac Cleaner – in no time and with minimal effort.
Run the Finder. In the Go menu, select Go to Folder and enter ~/Library/Application Support/MobileSync/Backup/. Delete all outdated backups on your startup disk.
Now restart your computer. No longer see the message that says “Your startup disk is almost full”? Then your disk should be fine.
Instead of going through all the above procedures, you can simply download Movavi Mac Cleaner and start working with it right away. This app will save you a lot of time and help you solve most startup disk problems.