Hey there! Let's work through this VNC issue you're facing—those locking errors and confusing quota messages can be tricky, but we'll break down why they happen and the best ways to fix them.

Why This Happens #

1. Stale Lock on Xauthority File #

The ~/.Xauthority file manages authentication for X11 sessions (which VNC relies on). When you start VNC, it creates a temporary lock file (~/.Xauthority.lock) to prevent multiple processes from editing it at once. If your last VNC session crashed or exited abnormally, this lock file might not get cleaned up. That's when you see the "error in locking authority file" message—VNC thinks another process is already using the file.

2. Quota Limits (Even With Free Disk Space) #

The "disk quota exceeded" message doesn't always mean the entire disk is full. Most likely, your user account has a dedicated quota set by the system administrator. Even if the disk has 16GB of free space, if your user has used up their allocated quota (e.g., 5GB out of a 5GB limit), any write operation (like updating the Xauthority file) will trigger that error.

Step-by-Step Solutions #

Temporary Quick Fix (Works Now, But Might Recur) #

If you just need to get VNC running immediately, deleting the Xauthority file and its lock will do the trick—VNC will regenerate a fresh one:

rm -f ~/.Xauthority ~/.Xauthority.lock

But this is a band-aid; let's tackle the root cause.

Optimal, Long-Term Fixes #

1. Check Your User Quota First
   Verify if your user account has hit its quota limit with this command:

   quota -u $(whoami)
   

   • If you see used is equal to limit, you need to clean up files in your home directory (delete old logs, unused apps, etc.) or ask your admin to increase your quota.
   • If quota is fine, move on to the next steps.

2. Kill Stale VNC Processes
   Abandoned VNC processes might be holding onto the Xauthority lock. Find and terminate them:

   # List all VNC-related processes
   ps aux | grep vnc
   # Kill the stale process (replace <PID> with the process ID from the output)
   kill -9 <PID>
   

3. Only Delete the Lock File (Preserve Xauthority)
   Instead of deleting the entire Xauthority file (which stores your session auth data), just remove the stale lock:

   rm -f ~/.Xauthority.lock
   

   This lets VNC use your existing Xauthority file without regenerating it, avoiding potential permission issues.

4. Fix Xauthority Permissions
   Sometimes incorrect file permissions can cause locking issues. Ensure the file belongs to you:

   # Check current permissions
   ls -l ~/.Xauthority
   # Fix ownership if needed (replace your_username and your_group with your actual details)
   chown your_username:your_group ~/.Xauthority
   

Final Notes #

Start with checking your quota—that's the most common hidden culprit when you have free disk space but get quota errors. Then clean up stale processes and locks, and you'll avoid having to delete Xauthority every time.

内容的提问来源于stack exchange，提问作者achref