Add swapfile to both hosts.

states/swapfile/init.sls

@@ -0,0 +1,16 @@
+{% set swapfile = salt['pillar.get']('swapfile', {}) %}
+{% set size = swapfile.get('size', grains["mem_total"]) %}
+{% set path = swapfile.get('path', '/swapfile') %}
+
+{{ path }}:
+  cmd.run:
+    - name: |
+        swapon --show=NAME --noheadings | grep -q "^{{ path }}$" && swapoff {{ path }}
+        rm -f {{ path }}
+        fallocate -l {{ size }}M {{ path }}
+        chmod 0600 {{ path }}
+        mkswap {{ path }}
+    - unless: bash -c '[[ $(($(stat -c %s {{ path }}) / 1024**2)) = {{ size }} ]]'
+
+  mount.swap:
+    - persist: true

states/top.sls

@@ -1,9 +1,10 @@
 base:
   '*':
     - common
-  
+
   'hedwig.lunch.org.uk':
     - debian
+    - swapfile
     - apache
     - mariadb
     - backup
@@ -18,6 +19,7 @@ base:
 
   'scabbers.lunch.org.uk':
     - debian
+    - swapfile
     - certificates
     - apache
     - backup