diff --git a/defaults/main.yml b/defaults/main.yml
index 84f47bd..26d4023 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -185,13 +185,15 @@ properties: {}
 # host.
 lxc_container_journal_link: true
 
-# Enable or Disable the BTRFS quota system for the "/var/lib/machines" mount
-# point. More information on the BTRFS quota system can be found here:
+# Enable or Disable the BTRFS quota system, which is used for the
+# "/var/lib/machines" mount point (for the machinectl backing store), or for
+# any containers with a btrfs backing store. More information on the BTRFS
+# quota system can be found here:
 #  * https://btrfs.wiki.kernel.org/index.php/Quota_support
-lxc_host_machine_quota_disabled: false
+lxc_host_btrfs_quota_disabled: false
 
-# Set the default qgroup limits used for file system quotas. The default is
-# "none". See the following documentation for more information:
+# Set the default qgroup limits used for btrfs file system quotas. The default
+# is "none". See the following documentation for more information:
 #  * https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-qgroup
-lxc_host_machine_qgroup_space_limit: none
-lxc_host_machine_qgroup_compression_limit: none
+lxc_host_btrfs_qgroup_space_limit: none
+lxc_host_btrfs_qgroup_compression_limit: none
diff --git a/releasenotes/notes/lxc-host-machine-vars-5d11b1f269167fd3.yaml b/releasenotes/notes/lxc-host-machine-vars-5d11b1f269167fd3.yaml
new file mode 100644
index 0000000..5328612
--- /dev/null
+++ b/releasenotes/notes/lxc-host-machine-vars-5d11b1f269167fd3.yaml
@@ -0,0 +1,15 @@
+---
+fixes:
+  - |
+    When using LXC containers with a copy-on-write back-end, the ``lxc_hosts``
+    role execution would fail due to undefined variables with the
+    ``nspawn_host_`` prefix. This issue has now been fixed.
+deprecations:
+  - |
+    The following variable name changes have been implemented in order to
+    better reflect their purpose.
+
+    * ``lxc_host_machine_quota_disabled`` -> ``lxc_host_btrfs_quota_disabled``
+    * ``lxc_host_machine_qgroup_space_limit`` -> ``lxc_host_btrfs_qgroup_space_limit``
+    * ``lxc_host_machine_qgroup_compression_limit`` -> ``lxc_host_btrfs_qgroup_compression_limit``
+
diff --git a/tasks/lxc_container_create_cow.yml b/tasks/lxc_container_create_cow.yml
index 8be646f..d091d73 100644
--- a/tasks/lxc_container_create_cow.yml
+++ b/tasks/lxc_container_create_cow.yml
@@ -38,23 +38,23 @@
   when:
     - lxc_container_info.rc != 0
 
-- name: Set the qgroup limits
+- name: Set the qgroup limits for btrfs backing stores
   block:
     - name: Set the qgroup size|compression limits on machines
       command: "btrfs qgroup limit {{ item }} /var/lib/lxc/{{ inventory_hostname }}"
       changed_when: false
       delegate_to: "{{ physical_host }}"
       with_items:
-        - "-e {{ nspawn_host_qgroup_space_limit }}"
-        - "-c {{ nspawn_host_qgroup_compression_limit }}"
+        - "-e {{ lxc_host_btrfs_qgroup_space_limit }}"
+        - "-c {{ lxc_host_btrfs_qgroup_compression_limit }}"
       when:
-        - not nspawn_host_machine_quota_disabled
+        - not (lxc_host_btrfs_quota_disabled | bool)
   rescue:
     - name: Notice regarding quota system
       debug:
         msg: >-
           There was an error processing the setup of qgroups. Check the system
           to ensure they're available otherwise disable the quota system by
-          setting `nspawn_host_machine_quota_disabled` to true.
+          setting `lxc_host_btrfs_quota_disabled` to true.
   when:
     - lxc_container_backing_store == 'btrfs'
diff --git a/tasks/lxc_container_create_machinectl.yml b/tasks/lxc_container_create_machinectl.yml
index 1d0a585..711e33f 100644
--- a/tasks/lxc_container_create_machinectl.yml
+++ b/tasks/lxc_container_create_machinectl.yml
@@ -35,14 +35,14 @@
       changed_when: false
       delegate_to: "{{ physical_host }}"
       with_items:
-        - "-e {{ lxc_host_machine_qgroup_space_limit }}"
-        - "-c {{ lxc_host_machine_qgroup_compression_limit }}"
+        - "-e {{ lxc_host_btrfs_qgroup_space_limit }}"
+        - "-c {{ lxc_host_btrfs_qgroup_compression_limit }}"
       when:
-        - not lxc_host_machine_quota_disabled
+        - not (lxc_host_btrfs_quota_disabled | bool)
   rescue:
     - name: Notice regarding quota system
       debug:
         msg: >-
           There was an error processing the setup of qgroups. Check the system
           to ensure they're available otherwise disable the quota system by
-          setting `lxc_host_machine_quota_disabled` to true.
+          setting `lxc_host_btrfs_quota_disabled` to true.