move package repo management documentation

admin-guide/configuration.md

@@ -8,7 +8,7 @@ Here starts a so far small collections of configuration guides for sysadmins of
 ## Software Management
 - [Package Installation](configuration/packages)
 - [Automated Package Updates](configuration/package_updates)
-- [Adding Package Repositories](configuration/package_repositories)
+- [Selecting Package Repositories](configuration/package_repositories)
 - [Managing Services with Systemd)](configuration/services)
 
 ## Basic Setup

admin-guide/configuration/package_repositories.md

@@ -1,4 +1,4 @@
-# Management of Package Repositories
+# Selecting Package Repositories
 
 ## Package Repository Lists
 Also for configuring package repositories our configuration management works with lists containing the names of the repositories to be installed.

admin-guide/configuration/package_updates.md

@@ -10,3 +10,10 @@ The automatic updates are controlled in Hiera:
 | `base::automatic_updates::kernel`   | `false`    | define if new kernel packages also should be installed automatically          |
 
 Note that the updates run on midnight, for `weekly` from Sunday to Monday. There is no automatic reboot, e.g. for kernel updates.
+
+---
+**Important**
+
+There will be no updates if you fix the package source to a snapshot/repo tag i.e. `rpm_repos::tag` or `yum_client::repo_tag` setting in Hiera point to a specfic snapshot.
+
+---