Docs: remove some bad recommendations

Change-Id: I401a073eb6225e90b6f9d6b2a32f33d22d1d7a79

doc/source/admin/production-architecture-guide.rst

@@ -157,9 +157,8 @@ several Docker configuration details relevant to Kolla operators.
 Storage driver
 --------------
 
-In certain distributions Docker storage driver defaults to devicemapper, which
-can heavily hit performance of builds and deploys. We suggest to use btrfs or
-aufs as driver. More details on which storage driver to use in
+While the default storage driver should be fine for most users, Docker offers
+more options to consider. For details please refer to
 `Docker documentation <https://docs.docker.com/engine/userguide/storagedriver/selectadriver/>`_.
 
 Volumes

doc/source/reference/deployment-and-bootstrapping/bootstrap-servers.rst

@@ -157,7 +157,7 @@ Configuration
 -------------
 
 The ``docker_storage_driver`` variable is optional. If set, it defines the
-`storage (graph) driver
+`storage driver
 <https://docs.docker.com/storage/storagedriver/select-storage-driver/>`__ to
 use for Docker.
 

doc/source/user/operating-kolla.rst

@@ -49,13 +49,7 @@ Limitations and Recommendations
    Varying degrees of success have been reported with upgrading the libvirt
    container with a running virtual machine in it. The libvirt upgrade still
    needs a bit more validation, but the Kolla community feels confident this
-   mechanism can be used with the correct Docker graph driver.
-
-.. note::
-
-   The Kolla community recommends the btrfs or aufs graph drivers for storing
-   data as sometimes the LVM graph driver loses track of its reference counting
-   and results in an unremovable container.
+   mechanism can be used with the correct Docker storage driver.
 
 .. note::