What To Do If Your Startup Disk Is Almost Full

If you’re getting this error message on your Mac: Your Startup Disk Is Almost Full, don’t worry. This is a common error and you can fix the full startup disk easily with the solutions in this post. Check it out.

If you’re a fan of Mac Pro/Air, you won’t be unfamiliar with the warning message: Your Startup Disk Is Almost Full.

And if you’re getting this full startup disk warning, don’t panic! This is a common error on Mac and you can fix the startup disk full error message easily.

This post introduces three parts:

1. Why is startup disk full on Mac
2. Ways to fix full startup disk manually
3. Clean up your Mac securely and automatically

1. Why is startup disk full on Mac

This part is about the information on the full startup disk warning. If you’ve already known something about this, you can skip to the second part:  ways to fix full startup disk.

What is the startup disk?

By default, your Mac starts up from its built-in hard disk, but a startup disk can be any storage device that contains an operating system compatible with your Mac. That is to say, your startup disk contains the operating system information, applications and user data.

How to check what my startup disk is?

It’s rather easy and direct to check what your startup disk is. You can follow the steps below to do:

1) Click the Apple icon at the upper left corner, and click About This Mac.

2) Under the Overview tab, you can see the Startup Disk information.

Why is my startup disk full on Mac?

Since you know what your startup disk is, it’s obvious that why your startup disk is almost full: lots of applications, photos, videos and documents are stored in your startup disk, and you should free up more storage space in your disk.

You can follow the steps below to see what’s taking up your disk storage:

1) Click the Apple icon at the upper left corner, and click About This Mac.

2) Click the Storage tab, and you can see the detailed information of your startup disk: how much space is available in your disk, and the categories that take up the space.

Note: If you are running an older version of OS X, you may have to first click More Info… and then click Storage.

If you’re getting Your startup disk is almost full warning on your Mac, you should really consider cleaning up your system disk and free up some more space. Otherwise, it can slow down your system and undermine your experience. To know how to fix the full startup disk, read on…

2. Ways to fix full startup disk manually

This post introduces 6 effective ways to fix the full startup disk issue and free up more storage space.

Note: Before getting started, it’s recommended to backup important data in your Mac using Time Machine.

Way 1: Clear cache files

One of the common methods to clean storage disk is to clean up cache files in your Mac.

1) Click Go > Go to Folder from the menu in the top.

2) Enter the Library folder path: ~/Labrary, then click Go.

3) Scroll down and double click the Caches folder.

4) Select the folders or items that take up most space, and more them to Trash.

Clearing up caches is normally safe and easy for your Mac.

Way 2: Delete unnecessary applications

There should be many applications installed in your Mac system, but some of them may not be used anymore. If that’s the case, you should really consider removing these applications and associated files from your Mac.

If applications are downloaded from the App Store:

1) Click the Launchpad icon on your Mac desktop.

2) Press and hold your mouse pointer over the application that should be uninstalled, and click the Delete button.

If the app doesn’t have the Delete icon, it can’t be uninstalled.

If applications are installed from elsewhere, moving the application to the Trash doesn’t make any sense, so make sure to go through your applications folder and get rid of all the apps you rarely use. If you don’t have time or patience, you can do this automatically with MacClean.

Way 3: Clean up your Downloads, Movies and Music folders

It’s usually overlooked to clean up downloads, movies and music folders in your Mac, and this should also take lots of space in your disk.

Follow the instructions below to clean up your Downloads:

1) Go to Finder > Downloads.

2) From the View menu, select As List.

3) Click Size to display the downloaded folders from large to small.

4) Select All or the large file size and move them to Trash.

Then go to the music and movie folders, and delete the items that you don’t use anymore.

Way 4: Delete old iTunes Library backups

If you have many iTunes backups in your Mac, you can just keep the most recent backups, and delete the old backups that you don’t need to have more space.

1) Click Finder to open it.

2) Click Go from the top menu and select Go to Folder.

3) Type ~/Music/iTunes/Previous iTunes Libraries, and click Go.

4) Delete the old backups that you don’t need.

Hope this helps in freeing up space when your startup disk is almost full.

Way 5: Delete iOS software updates

If you have updated your iOS devices on your Mac, those downloaded files should be stored in your Mac, and you wouldn’t need them anymore once your iOS devices have updated. So deleting those downloaded files should help clean up your disk. Here’s how to do it:

1) Click Finder to open it.

2) Click Go from the top menu and select Go to Folder.

3) Type ~/Library/iTunes/iPhone Software Updates and click Go. Then delete the software updates for iPhone.

4) Type ~/Library/iTunes/iPad Software Updates and click Go. Then delete the software updates for iPad.

This should spare some more space in your full startup disk.

Way 6: Empty Trash

Since we’ve moved so many files and data to the trash, you’d be surprised with the large space after emptying the trash.

1) Click and hold the Trash icon on your desktop.

2) Click Empty Trash.

3) Click Empty Trash to confirm.

4) Restart your Mac and this should fix your full startup disk.

3. Clean up your Mac securely and automatically

Manually cleaning your Mac when your startup disk is full requires time and skills.

If you don’t have time or patience, you can clear up your Mac automatically and securely with MacClean.

MacClean helps clean your Mac fast and securely with cutting-edge technologies and services. In addition to your familiar Mac cleaning and OS system maintaining features, it now arms with privacy and security protections to give you a state-of-the-art Mac experience.

1) Download MacClean in your Mac and run.

2) You can clean your system, optimize your Mac by navigating to the tools on the left menu tools.

3) Click each tool in turn to clean your Mac: Old Large Files to clean the old files in your Mac, and App Uninstaller helps remove your apps without leaving any junk files.

4) After optimizing your system, reboot your Mac to take effect.

That’s it. Hope this post helps with your startup disk is almost full error. Feel free to leave a comment below if you have any questions.

By Lillian Lai

Lillian, a Microsoft Certified Professional (MCP), is a technology enthusiast, longing to share the technical tips and solutions to computer problems. Also as a person who enjoys writing, she’s found the perfect match for writing and technology. When she’s not writing, you’ll find her either reading or playing mobile games.

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