add note about supported distros

Author: bedroge

docs/05_advanced.md

@@ -339,6 +339,10 @@ either in a user's own file space or even under `/cvmfs`.
 
 An advantage of this method is that the cache can be shared by several processes running on the same machines, even if you bind the mountpoint into multiple container instances.
 
+!!! note
+This currently only works on RHEL 6/7/8 and its derivatives, and SUSE 15 and its derivatives.
+
+
 ## 5.6 Using a configuration repository
 
 In the [first hands-on part of this tutorial](02_stratum0_client.md#22-setting-up-a-client) we have manually