Fix Guide: Mac "System Data" (Other) Storage is Full
Symptom: You receive a "Your disk is almost full" alert. When checking Storage settings, "System Data" (formerly "Other") is taking up hundreds of GBs, but you can't find the files in your Documents or Downloads.
Why this happens
"System Data" is a catch-all for local Time Machine snapshots, cache files, app support data, and old iOS backups. macOS is supposed to prune these automatically, but often fails if the drive gets too full for the "cleaner" to run.
Fix 1: Manual Snapshot Purge (Free)
Local Time Machine snapshots are the #1 culprit.
**Open Terminal**
Go to Applications > Utilities > Terminal.
**List Snapshots**
Type: `tmutil listlocalsnapshots /`
**Delete Snapshots**
Identify the date string from the list.
Type: `tmutil deletelocalsnapshots [date]` (replace [date] with your string).
Fix 2: Clearing the User Cache (Free)
**Navigate to Cache**
In Finder, press `Command + Shift + G`.
Paste: `~/Library/Caches`
**Remove Files**
Select the contents (Cmd+A).
Move to Trash.
*Note: Do not delete the Library folder itself.*
**System Restart**
Restart your Mac to allow the system to rebuild necessary caches.
Fix 3: The Automated "Deep Clean" Solution
When you need to reclaim 50GB+ in under 2 minutes.
Manual cleaning only scratches the surface. There are thousands of "hidden" system logs and broken DMG installers that Terminal commands won't easily find.
Recommended Tool: CleanMyMac X
- **Why it’s better:** It has a specialized "System Junk" module that safely identifies files even Apple's built-in "Optimize Storage" tool misses. It can typically reclaim 15-30% of your disk space instantly.
- **Bonus:** It includes a "Space Lens" feature that shows you exactly what "System Data" is made of in a visual map.
[Link: Reclaim your storage with CleanMyMac X]
Alternative: DaisyDisk
If you prefer a visual "treasure hunt" approach, DaisyDisk is the fastest tool to find exactly which folder is eating your drive.
[Link: Find hidden files with DaisyDisk]