document vgroot puppet module and RHEL8 default partition sizes

admin-guide/deployment/partitioning.rst

@@ -12,7 +12,7 @@ device name of the disk which should be used instead::
 
     bob node set-attr $FQDN system_disk=md126
 
-The default partition schema is:
+The default partition schema for RHEL 7 is:
 
    - create one primary ``/boot`` partition of 1Gb;
    - create the ``vg_root`` Volume Group that uses the rest of the disk;
@@ -22,6 +22,19 @@ The default partition schema is:
        - ``lv_var_log`` of 2 Gb size for ``/var/log``;
        - ``lv_tmp`` of 2 Gb size for ``/tmp``.
 
+For RHEL 8 it is:
+
+   - create one primary ``/boot`` partition of 1Gb;
+   - create the ``vg_root`` Volume Group that uses the rest of the disk;
+   - on ``vg_root`` create the following logical volumes:
+       - ``lv_root`` of 14 Gb size for ``/root``;
+       - ``lv_home`` of 2 Gb size for ``/home``;
+       - ``lv_var`` of 8 Gb size for ``/var``;
+       - ``lv_var_log`` of 3 Gb size for ``/var/log``;
+       - ``lv_var_tmp`` of 2 Gb size for ``/var/log``;
+       - ``lv_tmp`` of 2 Gb size for ``/tmp``.
+
+To increase these sizes, you might use :doc:`vgroot::path <../profiles/vgroot>` in Hiera.
 
 Custom Partitioning
 -------------------
@@ -34,3 +47,5 @@ The ``partitions`` attribute can take two values:
 
 If it is not possible to download the given URL the system fails-back to manual at installation time.
 Please also note that no check is done on the URL content. 
+
+Note that if you want to do add partitions outside of the on the system disk (while keeping above default partitioning for it), you might use Puppet and the `lvm Puppet module <https://forge.puppet.com/modules/puppetlabs/lvm>`_ instead to define the full LVM volume group.

admin-guide/puppet/profiles/vgroot.rst

@@ -19,7 +19,7 @@ vgroot                          hash      hiera_hash('vgroot::path')
 ``vgroot``
 ~~~~~~~~~~~
 
-A hash containing as key the name of the volume group (``/dev/mapper/vg_root-$NAME``) to be adjusted and the volume size as value. 
+A hash containing as key the name of the volume group (``/dev/mapper/vg_root-$NAME``) to be adjusted and the volume size as value::
 
   vgroot::path:
     lv_root: 20GB