Why do I need free space on my Mac’s startup disk?Īs your Mac runs software and completes different processes, it needs extra space to work in. If you have multiple disks or partitions, choose your startup disk from System Preferences. You can choose which drive to use as your startup disk from the System Preferences. Your startup disk is the drive your Mac boots up from by default. If you have multiple drives connected to your Mac - or if you split your drive into multiple partitions, as recommended for running beta software - only one of them is your startup disk. Normally there’s only one drive in a computer, so it holds all your documents and data as well - which is probably how it got filled up. What is my startup disk?įor those who don’t know, your startup disk is the hard drive in your computer that stores the operating software.

But if you’d rather skip them, click here to jump straight to our instructions for deleting files when your Mac startup disk is full. It’s useful to know the answers to these questions before you start clearing space on your disk. You’ll find the answers to a few common questions about startup disks below. Let’s start by explaining what we’re talking about.

Mac OS X: How to free up hard disk space.

How to check your hard disk space on your Mac.

Mac OS X: What is “Other” storage and how to remove.

How to use the new Storage Optimization features in macOS Sierra.

What is “Other” storage on iPhone or Mac and how do I get rid of it?.

If you have a recent backup, erase your startup disk and reinstall macOS.

Hold T to boot into Target Disk and access your data from a second Mac.

Open Disk Utility and run First Aid on your startup disk.

Bypass the Trash when you delete files with option+command+delete.

Boot into Safe Mode by holding the shift key during startup.

It’s tough to know where to start when you can’t even delete files anymore, but we’ve got you covered with these quick tips, explained in detail below:

How to create space on your Mac when the startup disk is full.

Erase your startup disk and reinstall macOS

Repair your startup disk using Disk Utility How to delete files on your Mac when the startup disk is full.

How do I find out how much free space I have on my startup disk?.

How much free space do I need on my startup disk?.

Why do I need free space on my Mac’s startup disk?.

Clean up my mac storage