How to fix startup disk full error on Mac

Mac insufficient storage space? Easily solve the problem of startup disk space urgently!

Mac systems usually run stably, and even if there are minor problems, restarting can be easily solved. But insufficient boot disk space is an exception, which can seriously affect the performance of your Mac. This problem is usually caused by excessive accumulation of outdated files, system logs, application caches, and other data, exceeding the recommended storage limits for macOS. These files are difficult to find and delete, and simply moving to the wastebasket does not solve the problem and require a thorough cleaning.

This article will guide you step by step how to avoid the "boot disk full" problem and provide effective solutions (tip: Just emptying the trash is not enough).

reason	Solution
Trash is full of deleted files	Empty the Trash: Right-click the Trash icon > Clear.
Application cache accumulation	Delete the application cache: Finder menu > Go to Folders > Enter ~/Library/Caches and find the application cache that is no longer in use.
A large number of old download files	Organize file sizes in the download folder: Sort files in the download folder by size in the finder, and then delete unnecessary files.
Repeat photos	Use Gemini and other software to delete duplicate photos.

Insufficient space? CleanMyMac helps you quickly clean up junk files and free up more space! Get it now on Setapp! Free trial! Safe and reliable!

What is a Mac boot disk?

The boot disk is your Mac's main hard drive from which macOS boots (hence the name). For most users, the boot disk (Macintosh HD) is the only hard disk on your Mac.

You can partition the boot disk into multiple parts and use an additional external hard disk to store files. In this case, the boot disk is the one that boots macOS.

What does "disk space almost full" mean?

When the hard disk approaches its capacity limit, you will receive a notification that "boot disk space is almost full."

This message indicates that all files have occupied more than 85% of boot disk space, which is the recommended storage space limit. If you ignore this notification and continue to add files, your Mac's performance will be negatively affected, resulting in disk errors and other issues.

How to check Mac disk space?

If you receive a "boot disk space is almost full" error, you should first check which files take up a lot of space before you can take optimization measures.

How to check Mac storage space:

1. Open System Settings
2. Go to General>Storage

An intuitive chart is displayed at the top, breaking down the file types that occupy Mac space, from iCloud Drive to applications, and macOS system files. If the chart is close to or exceeds 85% of storage capacity, immediate steps are needed to resolve this issue to avoid slowing down your Mac or losing unsaved files.

Scroll down to the next section and you will see a list of suggestions and a complete category. If you click the information icon next to each category, you will get more information and possible actions to reduce their use space.

How to fix boot disk full error?

Apple does not provide an easy way to delete hidden system folders and other junk files. You may now have a few GB of such files on your Mac, cached from old apps to iPhone backups.

Here is a simple list of things to refer to when you find that the boot disk is full:

Empty the wastebasket

If you never clear the trash, the files you deleted don't disappear from your Mac - they will be relocated (although in a more compact form). Emptying the Trash permanently deletes these files and frees up space on the boot disk.

How to clear the wastebasket:

1. Click the Trash icon in the Dock
2. Click "Clear"

Another method is to right-click the Trash icon and select "Empty Trash".

To avoid manually clearing the trash, you can enable automatic deletion of files in the trash after 30 days:

1. Turn on preferences in the finder ( Command , )
2. Switch to the Advanced tab
3. Check "Remove items from the trash after 30 days"

Delete the application cache

Every application you have installed on your Mac will leave system-related files and user preferences, which will remain even if you delete the application itself. Over time, these files, called caches, accumulate and take up a lot of space on the boot disk.

It's hard to delete all unwanted caches because it requires going into a system folder without explicit instructions, but you can try:

1. From the Finder menu bar, select Go to > Go to Folder (Shift Command G)
2. Enter ~/Library/Caches and press Enter
3. Find any apps you no longer have and will not need in the future
4. Move its folder to the trash

For a more thorough cleaning, you need to use automated applications such as CleanMyMac.

CleanMyMac can solve all the problems of deleting useless system files without any manual sorting. This is a powerful Mac system optimization application, which includes freeing up space, removing malware, improving privacy, optimizing system processes, uninstalling applications, and more.

How to delete application cache using CleanMyMac:

1. Download and launch the application.
2. Go to Clean > Scan.
3. Click "View all junk files".
4. Check User Cache Files (and other optional categories).
5. Click "Clean".

Delete old downloaded files

The "Download" folder in the Finder is the default location for all files downloaded from the Internet. This is why the Download folder accumulates files over the years, ultimately causing the Mac to slow down.

To quickly clean this folder, open it via Finder, right-click and group files by size. Start viewing the files from the top and delete unwanted files.

Back up large files

No matter how many unwanted files you delete, if the files you need to use (sometimes) take up a lot of space, you will continue to face the problem of boot disk full.

The solution is to back up large files that are not often used and remove them from your Mac. They can be accessed from the cloud or from external storage devices when needed.

The easiest way is to enable iCloud synchronization and sync all iCloud cloud disk files to the cloud. It is recommended to sync files between your device and the cloud. However, iCloud is not a backup solution—it is a synchronization solution. If you delete files from your Mac, they will also be deleted elsewhere.

A suitable backup solution that keeps your files safe, such as Get Backup Pro.

Get Backup Pro allows you to select the type of backup you want, from simple copy to incremental backup to versioned backup. You can back up selected files and folders to an external drive, or sync them between two Macs. There is the option to schedule a backup, or even make a bootable backup (for installing macOS itself).

Delete duplicate photos

Since we carry iPhones with us, it’s easy to take photos, and they tend to accumulate on our Mac much faster than we can view and delete unwanted photos.

The manual solution here is not feasible. This is why it is necessary to have a duplicate file finder and deleter on your Mac.

Gemini is the most powerful duplicate file finder on the market. It can scan any folder (or the entire Mac) on your Mac and find any duplicate files, from videos and photos to documents and presentations. Better yet, Gemini can look for similar files, such as photo variants or document drafts, and suggests that they be deleted. You can then free up space with one click.

How to delete duplicates using Gemini:

1. Start the application
2. Click the plus icon and select the folder to scan
3. Scan the duplicates
4. View duplicates
5. Delete any unwanted copies

Delete old system and user logs

System and user logs are text-based files that record various events occurring in macOS and third-party applications. While they don't usually take up a lot of space, it's a good habit to delete them occasionally.

How to manually delete system and user logs:

1. In the Finder, from the menu bar, select Go to > Go to Folder (Shift Command G)
2. Enter ~/Library/Logs and press Enter
3. Delete logs you know you don't need

A faster and safer way to delete logs is to use CleanMyMac:

1. Launch the application.
2. Click Clean > Scan.
3. Click "View All Junk Files" and select the logs you want to delete (corrupted login items, user log files, system log files, language files, user cache files, and other files - usually all of them are safe to delete).
4. Click "Clean".

Uninstall unused applications

Applications are one of the main occupants of disk space on your Mac. If you don't track them, they can quickly become a cause of insufficient boot disk space.

You can easily delete the app yourself. Open the Applications folder and move unwanted applications to the Trash. The problem is that most applications save auxiliary files elsewhere around the Mac, and you don't want to leave them behind.

The correct way to uninstall the application is to use CleanMyMac:

1. Open the application.
2. Click Apps > Scan on the left panel.
3. Click Manage My Applications > Uninstall Programs at the top of the CleanMyMac window.
4. Select the apps you don't need and delete them.

Delete unused languages

Many applications on your Mac include localizations in languages ​​that you may not use. They all take up extra space. Depending on the number of apps you install, this category may bloat to a few GB.

How to manually clean up unused languages:

1. Open the Applications folder ( Shift Command A )
2. Right-click on any application and select "Show package content"
3. Go to Contents > Resources
4. Delete files or folders in languages ​​you do not need (they have the .lproj extension)

Repeating the above for all applications on your Mac will take a lot of time. Instead, you can use CleanMyMac to delete all unused languages ​​in one click:

1. Open CleanMyMac.
2. Click Clean > Scan.
3. Click "View all junk files".
4. Select Language File.
5. Click "Clean".

Clean the desktop

Desktop plays a special role on your Mac. Think of it as a folder that is always open. Every time you view the desktop, your Mac must refresh it to make sure it displays the latest information. This is why the fewer files you keep on your desktop, the fewer resources your Mac uses.

If your desktop is cluttered, manually cleaning it can be the last thing on your to-do list. This is why you need to use Spotless to automate this process.

Spotless is a scheduling application that allows you to define specific rules to manage different types of files. For example, you might want to put all images into the Pictures folder. Once the rules are created, you simply select all the files on the desktop and drag and drop them into the Spotless icon in the menu bar and it will process them in seconds.

Delete old iOS backups

You may not realize this, but it is easy to accumulate more iOS backups than you need. They may take up a few GB of extra space for no reason.

How to delete unnecessary backups on your Mac:

1. Go to System Settings > General > Storage Space
2. Click the info icon next to the iOS file
3. Select any unwanted backups
4. delete……

If you want more control over everything that happens between your iPhone and Mac, you need AnyTrans for iOS.

AnyTrans for iOS is the ultimate iPhone manager that allows you to specify backups, transfer data, migrate between devices, convert photos, set ringtones, update apps, and more. All of this can be done in an easy-to-use interface.

As you can see, it is not that serious that the Mac boot disk is full. If you follow the steps above, you will free up space and immediately eliminate the warning.

Most importantly, the applications we mentioned, such as Gemini, CleanMyMac, Spotless, and Get Backup Pro, can help you, and you can try it for seven days with the Setapp trial.

Setapp is a platform with over 240 carefully selected Mac and iOS applications designed to solve any problem you can think of. Explore the collection for free now and see what you've missed.

Frequently Asked Questions

How to restore the system on my Mac without booting disk?

Because the boot disk contains all the system files that the Mac needs to run correctly, it is impossible to recover the Mac without the boot disk.

How to hide the "Disk Space Almost Full" notification on your Mac?

To hide the "Disk Space Almost Full" notification on your Mac, follow the list above to free up space.

Why does my Mac keep prompting that the boot disk is full?

If your Mac keeps prompting that the boot disk is full, it means your Mac has no more space for system operations. Delete unwanted files and applications to resolve this issue.

All images retain their original text format and location.

The above is the detailed content of How to fix startup disk full error on Mac. For more information, please follow other related articles on the PHP Chinese website!