volumemgr: load dm-snapshot kernel module

roles/float-base-volumemgr/tasks/main.yml

@@ -4,3 +4,9 @@
   with_items: "{{ float_enabled_services }}"
   loop_control:
     loop_var: service_name_iter
+
+- name: Configure kernel modules
+  template:
+    src: "modules.conf.j2"
+    dest: "/etc/modules-load.d/float-volumemgr.conf"
+  when: enable_lvm

roles/float-base-volumemgr/templates/modules.conf.j2

+# Force-load dm-snapshot to enable LVM snapshots
+# Normally this module is loaded on demand by LVM, however module loading is
+# disabled after boot is completed.
+dm-snapshot