diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..10e2983
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*.rrd
+*.svg
diff --git a/README.md b/README.md
index 548f7b5..a11725f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,11 @@
 # cagull-rrdtools
 
+## Prérequis
+
+Paquets Debian à installer :
+* `sysstats`
+* `rrdtools` 
+
 ## Objectif
 
 On cherche à mesurer les métriques de la machine virtuelle pour avoir une idée de ce qui s'y passe.
@@ -58,3 +64,65 @@ veth3cae73a: 4008409    1953    0    0    0     0          0         0   287234
 ```
 
 On a donc toutes les données de mesure que l'on voulait.
+
+## Stocker les mesures
+
+On utilise les RRDTools pour stocker et tracer les données.
+
+### Créer les bases
+
+cpu
+load
+mem
+fs
+net
+
+```
+rrdtool create cpu.rrd --start $(date +%s) --step 60 --no-overwrite \
+	DS:user:GAUGE:120:0:100 \
+	DS:nice:GAUGE:120:0:100 \
+	DS:sys:GAUGE:120:0:100 \
+	DS:iowait:GAUGE:120:0:100 \
+	DS:steal:GAUGE:120:0:100 \
+	DS:irq:GAUGE:120:0:100 \
+	DS:soft:GAUGE:120:0:100 \
+	DS:guest:GAUGE:120:0:100 \
+	DS:gnice:GAUGE:120:0:100 \
+	DS:idle:GAUGE:120:0:100 \
+	RRA:LAST:0.5:1:1440 \
+	RRA:AVERAGE:0.5:420:1440 \
+	RRA:AVERAGE:0.5:1860:1440 \
+	RRA:AVERAGE:0.5:21900:1440
+```
+
+```
+rrdtool update cpu.rrd $(date +%s):$(LANG=C sar -u ALL 0 -1 |tail -n1 |awk '{print $3,$4,$5,$6,$7,$8,$9,$10,$11,$12}' |tr ' ' ':');
+```
+
+Dans un `while true; do …; sleep 60; done`
+
+```
+rrdtool graph cpu-daily.png  --end now --start end-86400s \
+	DEF:user=cpu.rrd:user:AVERAGE \
+	DEF:nice=cpu.rrd:nice:AVERAGE \
+	DEF:sys=cpu.rrd:sys:AVERAGE \
+	DEF:iowait=cpu.rrd:iowait:AVERAGE \
+	DEF:steal=cpu.rrd:steal:AVERAGE \
+	DEF:irq=cpu.rrd:irq:AVERAGE \
+	DEF:soft=cpu.rrd:soft:AVERAGE \
+	DEF:guest=cpu.rrd:guest:AVERAGE \
+	DEF:gnice=cpu.rrd:gnice:AVERAGE \
+	DEF:idle=cpu.rrd:idle:AVERAGE \
+	AREA:user:STACK \
+	AREA:nice:STACK \
+	AREA:sys:STACK \
+	AREA:iowait:STACK \
+	AREA:steal:STACK \
+	AREA:irq:STACK \
+	AREA:soft:STACK \
+	AREA:guest:STACK \
+	AREA:gnice:STACK \
+	AREA:idle:STACK
+```
+
+