diff --git a/dicos/70_prometheus.xml b/dicos/70_prometheus.xml
index 9d57761..1d2050b 100644
--- a/dicos/70_prometheus.xml
+++ b/dicos/70_prometheus.xml
@@ -1,7 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <creole>
     <files>
-        <file filelist='prometheus'   name='/etc/prometheus/prometheus.yml'          mkdir='True' rm='True'/>
+		<file filelist='prometheus'   name='/etc/default/prometheus' source='prometheus.defaults'  mkdir='True' rm='True'/>
+        <file filelist='prometheus'   name='/etc/prometheus/prometheus.yml'          mkdir='Trues' rm='True'/>
         <file filelist='alertmanager' name='/etc/prometheus/alertmanager.yml'        mkdir='True' rm='True'/>
 		<file filelist='alertmanager' name='/etc/prometheus/rules.d/alert-rules.yml' mkdir='True' rm='True'/>
         <file filelist='grafana'      name='/etc/grafana/grafana.ini'                mkdir='True' rm='True'/>
@@ -30,6 +31,9 @@
             <variable name='activerAlertmanager' type='oui/non' description="Activer le service d'alertes">
                 <value>oui</value>
             </variable>
+			<variable name='promStorageRetention' type='number' description='Durée de rétention des métriques (en heures)'>
+				<value>24</value>
+			</variable>
             <variable name='prometheusJobName' type='string' description="Nom du job ajouté au label">
                 <value>prometheus</value>
             </variable>
diff --git a/tmpl/prometheus.defaults b/tmpl/prometheus.defaults
new file mode 100644
index 0000000..fad44bf
--- /dev/null
+++ b/tmpl/prometheus.defaults
@@ -0,0 +1 @@
+PROMETHEUS_OPTS='--config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path=/var/lib/prometheus/data --storage.local.retention=%%{promStorageRetention}h"