Updated Mount (markdown)

Mount.md

@@ -156,4 +156,23 @@ Threads fairness:
     execution time (avg/stddev):   299.4514/0.00
 
 
-```
+```
+
+### Unmount ###
+
+Sometimes `weed mount` can not start if the last mount process was not cleaned up.
+
+You can clean up with these commands. Try any of them until it works:
+
+```
+// on mac
+sudo umount /the/mounted/dir
+diskutil unmount force /the/mounted/dir
+sudo umount -f /the/mounted/dir
+sudo umount -l /the/mounted/dir
+
+// on linux
+sudo umount -f /the/mounted/dir
+sudo umount -l /the/mounted/dir
+
+```