Fix macOS "System Logs" Filling Disk

Is your Mac's storage disappearing due to massive log files in /var/log?

Recommended Troubleshooting Tool

Before proceeding with manual fixes, we recommend using CleanMyMac X. The gold standard for identifying hidden System Data bloat and runaway log files.

- [Download CleanMyMac X Free Here](#)

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The Symptom

"System Data" takes up 50GB+ and a quick check shows system.log or asl folders are enormous.

The Fix

1. Purge System Logs

sudo rm -rf /private/var/log/*
sudo rm -rf /private/var/folders/*

1. Disable Aggressive Logging

sudo log config --mode "level:default"

1. Maintenance Scripts

Run the hidden macOS maintenance scripts:

sudo periodic daily weekly monthly

Fix 3: The Automated "System Data" Solution

When you want to stop the bloat from coming back.

Manual purging is temporary. If you don't find the app that is "spamming" your logs, the storage will be full again within days.

Recommended Tool: CleanMyMac X

- System Junk: This is the most efficient way to clear logs. It doesn't just delete them; it identifies the *cause* of the bloat and helps you uninstall the faulty apps responsible for the massive log files.

- Space Lens: Provides a visual map of your storage, showing you exactly which folder (like /var/log) is eating your drive.

[Link: Reclaim your storage with CleanMyMac X]

Pro Tip

Large logs are usually caused by a single app crashing in the background and "spamming" the system log. Use log stream --level debug to see which app is the culprit.