macOS Mojave系统存储占用空间过大问题求助

开发者阿泽

2026-5-7

Hey there, let's tackle this Mac storage nightmare together—170+GB eaten up by the system is way too much, and it makes sense that generic cleaning tools aren't fixing it. Let's get granular with where your space is going and how to reclaim it.

1. First: Pinpoint exactly what's taking up space

System storage can be vague, so let's bypass the built-in "About This Mac" delay and use terminal commands to get real numbers:

Open Terminal (found in Applications > Utilities)
Run this command to see the size of every top-level folder on your data volume:
```
du -sh /System/Volumes/Data/*
```
This will show you which folders (like Library, Users, Applications) are the biggest culprits.
For even deeper dives, run this to find files over 10GB:
```
find /System/Volumes/Data -type f -size +10G
```

You can also check the built-in Storage Management: Go to Apple menu > About This Mac > Storage > Manage. Look for categories like "Large Files" or "Old Files"—but the terminal commands are way more accurate for system-level space.

2. Clean up the biggest hidden space hogs

These are the most common offenders that cleaning tools often miss:

Time Machine Local Snapshots
Your Mac automatically takes snapshots for Time Machine, even if you don't have an external drive connected. These can balloon to tens of GB.
- List all local snapshots:
```
tmutil listlocalsnapshots /
```
- Delete a specific snapshot (replace the name with yours):
```
tmutil deletelocalsnapshots 2024-05-20-123456
```
- Pro tip: After deleting, run tmutil thinlocalsnapshots / 10000000000 1 to force thin remaining snapshots.
System & User Caches
Caches build up over time and can get massive.
- For system-wide caches (use sudo carefully—check sizes first!):
```
du -sh /Library/Caches/*
sudo rm -rf /Library/Caches/*
```
- For your user caches (safer to delete):
  Open Finder, press Cmd+Shift+G, type ~/Library/Caches, and delete everything inside. Don't worry—apps will rebuild what they need.
Old iOS Backups
If you've backed up iPhones/iPads to your Mac, these backups live here: ~/Library/Application Support/MobileSync/Backup. Check the folder sizes—delete any backups for devices you no longer own.
Unfinished System Updates
Stuck update install packages take up space in /Library/Updates. Open that folder and delete any old .pkg files that aren't currently being used.

3. Fix APFS-specific space issues

Most modern Macs use APFS, which has hidden features that can eat space:

APFS Snapshots
These are different from Time Machine snapshots. List them with:
```
diskutil apfs listSnapshots /
```
Delete unnecessary ones with:
```
diskutil apfs deleteSnapshot / -uuid <SnapshotUUID>
```
(Replace <SnapshotUUID> with the UUID from the list command.)
Space Sharing Glitches
Sometimes APFS doesn't correctly report free space. Run this command to repair the disk (you'll need to restart into Recovery Mode if it can't repair while running):
```
diskutil apfs repairVolume /System/Volumes/Data
```

4. Advanced (but safe) cleanups

Only do these if you're sure you don't need the files:

Migration Data: If you migrated from an old Mac, check /Library/SystemMigration—this folder can hold gigabytes of old system data you don't need anymore.
VMware/Parallels Images: If you run Windows or other OSes via virtual machines, their disk images are huge. Look in ~/Documents/Parallels or ~/Documents/VMware Fusion and delete any unused images.
Mail Attachments: Mail stores all attachments locally by default. Open Mail, go to Mail > Settings > Accounts > Download Attachments, and set it to "Recent" or "None". You can also delete old attachments by searching for large files in ~/Library/Mail.

After cleaning, restart your Mac and check the storage again—you should see a significant drop in system storage usage.

内容的提问来源于stack exchange，提问作者Vivek Garg