When the Mac startup disk achieves its absolute performance, this means 2 things, precisely speaking 2 consequences: Your Mac's storage space will get to its limit very soon. The disc will work slowly. Most people do not know, actually, that their Mac is converting a free startup disk space into virtual memory, which you use for daily operations. Determining if you have a large amount of 'System' disk usage To see if this method will help you reclaim some disk space we need to check the macOS System Information. Click the from your desktop. Click About This Mac. Clean Up Your Mac Of course, the easiest way to create more space is to clean up the files on your MacBook. There are many tips you can try to create space on macOS. Apple provides all the tools you need to clear up gigabytes of space. To be sure that your computer functions properly, you should aim for at least 10%-15% of free disk space at all times. To help free up more of the storage space on your Mac, we are going to. If you need more space, you can change the file back to online only. Just right-click the file and select Free up space. Only files that you mark as Always keep on this device have the green.
Optimised Storage helps you save storage space by storing your content in iCloud and making it available on demand:
- When storage space is needed, files, photos, films, email attachments and other files that you rarely use are stored in iCloud automatically.
- Each file stays exactly where you last saved it, and will download when you open it.
- Files that you've used recently remain on your Mac, along with optimised versions of your photos.
If you haven't yet upgraded to macOS Sierra or later, find out about other ways to free up storage space.
Need More Disk Space Mac
Find out how much storage is available on your Mac
Choose Apple menu > About This Mac and then click Storage. Each segment of the bar is an estimate of the storage space used by a category of files. Move your pointer over each segment for more detail.
Click the Manage button to open the Storage Management window, pictured below.
Manage storage on your Mac
The Storage Management window offers recommendations for optimising your storage. If some recommendations have already been turned on, you will see fewer recommendations.
Store in iCloud
Click the Store in iCloud button and then choose from these options:
- Desktop and Documents. Store all files from these two locations in iCloud Drive. When storage space is needed, only the files you recently opened are kept on your Mac, so that you can work offline easily. Files only stored in iCloud will display a download icon , which you can double-click to download the original file. Find out more about this feature.
- Photos. Store all original, full-resolution photos and videos in iCloud Photos. When storage space is needed, only space-saving (optimised) versions of photos are kept on your Mac. To download the original photo or video, just open it.
- Messages. Store all messages and attachments in iCloud. When storage space is needed, only the messages and attachments you recently opened are kept on your Mac. Find out more about Messages in iCloud.
Storing files in iCloud uses the storage space in your iCloud storage plan. If you reach or exceed your iCloud storage limit, you can either buy more iCloud storage or make more iCloud storage available. iCloud storage starts at 50 GB for $0.99 (USD) a month, and you can purchase additional storage directly from your Apple device. Find out more about the prices in your region.
Optimise Storage
Click the Optimise button to save space by automatically removing films and TV programmes you've watched. When storage space is needed, films or TV programmes that you've purchased from Apple and have already watched will be removed from your Mac. Click the download icon next to a film or TV programme to download it again.
Your Mac will also save space by only keeping recent email attachments on this Mac when storage space is needed. You can manually download any attachments at any time by opening the email or attachment, or saving the attachment to your Mac.
Optimising storage for films, TV programmes and email attachments doesn't require iCloud storage space.
Empty Bin Automatically
Empty Bin Automatically permanently deletes files that have been in the Bin for more than 30 days.
Reduce Clutter
Reduce Clutter helps you identify large files and files you may no longer need. Click the Review Files button and then choose any of the file categories in the sidebar, such as Applications, Documents, Music Creation or Bin.
You can delete the files in some categories directly from this window. Other categories show the total storage space used by the files in each app. You can then open the app and decide whether to delete files from within it.
Find out how to re-download apps, music, films, TV programmes and books.
Where to find the settings for each feature
Buy More Disk Space Mac
The button for each recommendation in the Storage Management window affects one or more settings in other apps. You can also control these settings directly within each app.
- If you're using macOS Catalina or later, choose Apple menu > System Preferences, click Apple ID, and then select iCloud in the sidebar: Store in iCloud turns on the Optimise Mac Storage setting on the right. To turn off iCloud Drive entirely, deselect iCloud Drive.
- If you're using macOS Mojave or earlier, choose Apple menu > System Preferences, click iCloud, then click Options next to iCloud Drive. Store in iCloud turns on the Desktop & Documents Folders and Optimise Mac Storage settings.
- In Photos, choose Photos > Preferences and then click iCloud. Store in iCloud selects iCloud Photos and Optimise Mac Storage.
- In Messages, choose Messages > Preferences, then click iMessage. Store in iCloud selects Enable Messages in iCloud.
- If you're using macOS Catalina or later, open the Apple TV app, choose TV > Preferences from the menu bar, then click Files. Optimise Storage selects 'Automatically delete watched films and TV programmes'.
- In you're using macOS Mojave or earlier, open iTunes, choose iTunes > Preferences from the menu bar, then click Advanced. Optimise Storage selects 'Automatically delete watched films and TV programmes'.
- In Mail, choose Mail > Preferences from the menu bar and then click Accounts. In the Account Information section on the right, Optimise Storage sets the Download Attachments menu to either Recent or None.
Empty Bin Automatically: From the Finder, choose Finder > Preferences, then click Advanced. Empty Bin Automatically selects 'Remove items from the Bin after 30 days'.
Other ways that macOS automatically helps to save space
With macOS Sierra or later, your Mac will take these additional steps automatically to save storage space:
- Detects duplicate downloads in Safari, keeping only the most recent version of the download
- Reminds you to delete used app installers
- Removes old fonts, languages and dictionaries that aren't being used
- Clears caches, logs and other unnecessary data when storage space is needed
How to free up storage space manually
Even without using the Optimised Storage features described in this article, you can take other steps to make more storage space available:
- Music, films and other media can use a lot of storage space. Find out how to delete music, films and TV programmes from your device.
- Delete other files that you no longer need by moving them to the Bin, then emptying the Bin. The Downloads folder is good place to look for files that you may no longer need.
- Move files to an external storage device.
- Compress files.
- Delete unneeded email: In the Mail app, choose Mailbox > Erase Junk Mail. If you no longer need the email in your Deleted Items mailbox, choose Mailbox > Erase Deleted Items.
Learn more
- The Storage pane of About This Mac is the best way to determine the amount of storage space available on your Mac. Disk Utility and other apps may show storage categories, such as Not Mounted, VM, Recovery, Other Volumes, Free or Purgeable. Don't rely on these categories to understand how to free up storage space or how much storage space is available for your data.
- When you duplicate a file on an APFS-formatted volume, that file doesn't use additional storage space on the volume. Deleting a duplicate file only frees up the space required by any data that you might have added to the duplicate. If you no longer need any copies of the file, you can recover all of the storage space by deleting both the duplicate and the original file.
- If you're using a pro app and Optimise Mac Storage, find out how to make sure your projects are always on your Mac and able to access their files.
So, your Mac is running out of storage. You try to figure out what's taking up your disk space by clicking the Apple logo on the top-left of the screen, selecting About This Mac, and hitting the Storage tab.
To your surprise, you see a yellow bar representing 'System' that seems to occupy way more space than you think it should. In the example above, it only shows 207 GB, but take a look at this Apple discussion — some Mac users report that System Storage takes an astonishing 250 GB.
Worse yet, you have no idea what's included in 'System' storage, because clicking the 'Manage' button brings you to this System Information window… and the 'System' row is greyed out.
Why does my Mac system require so much space?
What does it contain?
Is it safe to remove some of those system files?
How do I regain more storage space?
Questions like these may easily get to your head. Although my Mac now has a good amount of disk space available, I'm always wary of files that are taking up more space than they should.
I have no idea why 'System' is greyed out while 'Documents,' 'System Junk,' 'Trash,' etc. allow you to review the files based on size and type. My hunch is that Apple does this on purpose to prevent users from deleting system files that could lead to serious issues.
What Files Are Included in System Storage on Mac?
During my research, I found many people report that Apple counts iTunes backup files and app caches (e.g. Adobe video cache files) in the System category.
Since it's greyed out and we are unable to click on that category for deeper analysis, we'll have to use a third-party app to assist.
CleanMyMac X is perfect for this kind of analysis. Since I tested the app in our best Mac cleaner review, it immediately came to my head when I saw 'System' was greyed out in Storage. Note that CleanMyMac isn't freeware, but the new 'Space Lens' feature is free to use and it allows you to scan your Macintosh HD, and then show you an in-depth overview of what's taking up disk space on your Mac.
Step 1:Download CleanMyMac and install the app on your Mac. Open it, under 'Space Lens' module, first click the yellow 'Grant Access' button to allow the app to access your Mac files and then select 'Scan' to get started.
Step 2: Wow mac os x. Soon it'll show you a folder/file tree and you can hover your cursor over each block (i.e. a folder). There you can find more details. In this case, I clicked 'System' folder to continue.
Step 3: The file breakdown below indicates that some Library and iOS Support files are the culprits.
How to free up storage space manually
Even without using the Optimised Storage features described in this article, you can take other steps to make more storage space available:
- Music, films and other media can use a lot of storage space. Find out how to delete music, films and TV programmes from your device.
- Delete other files that you no longer need by moving them to the Bin, then emptying the Bin. The Downloads folder is good place to look for files that you may no longer need.
- Move files to an external storage device.
- Compress files.
- Delete unneeded email: In the Mail app, choose Mailbox > Erase Junk Mail. If you no longer need the email in your Deleted Items mailbox, choose Mailbox > Erase Deleted Items.
Learn more
- The Storage pane of About This Mac is the best way to determine the amount of storage space available on your Mac. Disk Utility and other apps may show storage categories, such as Not Mounted, VM, Recovery, Other Volumes, Free or Purgeable. Don't rely on these categories to understand how to free up storage space or how much storage space is available for your data.
- When you duplicate a file on an APFS-formatted volume, that file doesn't use additional storage space on the volume. Deleting a duplicate file only frees up the space required by any data that you might have added to the duplicate. If you no longer need any copies of the file, you can recover all of the storage space by deleting both the duplicate and the original file.
- If you're using a pro app and Optimise Mac Storage, find out how to make sure your projects are always on your Mac and able to access their files.
So, your Mac is running out of storage. You try to figure out what's taking up your disk space by clicking the Apple logo on the top-left of the screen, selecting About This Mac, and hitting the Storage tab.
To your surprise, you see a yellow bar representing 'System' that seems to occupy way more space than you think it should. In the example above, it only shows 207 GB, but take a look at this Apple discussion — some Mac users report that System Storage takes an astonishing 250 GB.
Worse yet, you have no idea what's included in 'System' storage, because clicking the 'Manage' button brings you to this System Information window… and the 'System' row is greyed out.
Why does my Mac system require so much space?
What does it contain?
Is it safe to remove some of those system files?
How do I regain more storage space?
Questions like these may easily get to your head. Although my Mac now has a good amount of disk space available, I'm always wary of files that are taking up more space than they should.
I have no idea why 'System' is greyed out while 'Documents,' 'System Junk,' 'Trash,' etc. allow you to review the files based on size and type. My hunch is that Apple does this on purpose to prevent users from deleting system files that could lead to serious issues.
What Files Are Included in System Storage on Mac?
During my research, I found many people report that Apple counts iTunes backup files and app caches (e.g. Adobe video cache files) in the System category.
Since it's greyed out and we are unable to click on that category for deeper analysis, we'll have to use a third-party app to assist.
CleanMyMac X is perfect for this kind of analysis. Since I tested the app in our best Mac cleaner review, it immediately came to my head when I saw 'System' was greyed out in Storage. Note that CleanMyMac isn't freeware, but the new 'Space Lens' feature is free to use and it allows you to scan your Macintosh HD, and then show you an in-depth overview of what's taking up disk space on your Mac.
Step 1:Download CleanMyMac and install the app on your Mac. Open it, under 'Space Lens' module, first click the yellow 'Grant Access' button to allow the app to access your Mac files and then select 'Scan' to get started.
Step 2: Wow mac os x. Soon it'll show you a folder/file tree and you can hover your cursor over each block (i.e. a folder). There you can find more details. In this case, I clicked 'System' folder to continue.
Step 3: The file breakdown below indicates that some Library and iOS Support files are the culprits.
The interesting part is that the System file size shown in CleanMyMac is much smaller than the size shown in System Information. This puzzles me and makes me believe that Apple definitely has counted some other files (not real system files) in the System category.
What are they? I have no clue, honestly. But as reported by other Mac users who experienced the same issue, they said Apple also considers app caches and iTunes backup files as System files.
Out of curiosity, I ran CleanMyMac again for a quick scan. That app found 13.92 GB in iTunes Junk. Further review revealed that the junk files are old iOS device backups, software updates, broken downloads, etc.
But even after adding this amount to the original system files returned by CleanMyMac X, the total size is still a bit less than what's returned in System Information.
If cleaning the System Storage is still not enough to bring your Mac available disk space to a normal level (i.e. 20% or more), see below.
What Else Can I Do to Reclaim More Disk Space?
There are tons of ways out there. Here are a few of my favorites that should help you get back a decent amount of space quickly.
1. Sort all files by size and delete old large files.
Open Finder, go to Recents and look at the Size column. Click on it to sort all recent files by file size (from large to small). You'll have a clear overview of what items are eating up a large amount of space, e.g. From 1 GB to 10 GB, and from 100 MB to 1 GB.
On my MacBook Pro, I found a few large videos that could be transferred to an external drive.
Note: If the Size column doesn't show up, click on the Settings icon and select Arrange By > Size.
2. Remove duplicate files.
Don't forget those duplicates and similar files! They can stack up without you being aware of it. Finding them is sometimes time-consuming. That's what Gemini 2 is designed for. Simply select a few frequently used folders (e.g. Documents, Downloads, etc.) in the main zone of Gemini.
It then scans them and returns all the duplicate files that might be worth removing. Of course, it's always a good practice to review them before doing so. You can also read more from our detailed Gemini review here. Will high sierra run on my mac.
Wrapping It Up
Ever since Apple introduced the Optimized Storage feature, Mac users got the option of saving space by storing content in the cloud. Apple also has several new tools that make it easy to find and remove unneeded files.
That bar under the Storage tab is beautiful. It does allow you to get a quick overview of what's taking up the most space on our hard drive. However, it still lacks insights into the 'System' category as it's greyed out.
Hopefully, the guides above have helped you figure out the reasons you've got so much 'System' data, and most importantly you've reclaimed some disk space — especially for new MacBooks pre-installed with flash storage — every gigabyte is precious!
