<p>Installed Rancher server and 2 Rancher agents in Vagrant. Then switch to K8S environment from Rancher server.</p>

<p>On Rancher server host, installed <code>kubectl</code> and <code>helm</code>. Then installed <code>Prometheus</code> by <code>Helm</code>:</p>

<pre><code>helm install stable/prometheus
</code></pre>

<p>Now check the status from Kubernetes dashboard, there are 2 pods pending:
<a href="https://i.stack.imgur.com/bl8Hn.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bl8Hn.png" alt="enter image description here"></a></p>

<p>It noticed <code>PersistentVolumeClaim is not bound</code>, so aren't the K8S components been installed default with Rancher server?</p>

<p>(another name, same issue)
<a href="https://i.stack.imgur.com/jBGUy.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jBGUy.png" alt="enter image description here"></a></p>

<h1>Edit</h1>

<pre><code>&gt; kubectl get pvc
NAME                                   STATUS    VOLUME    CAPACITY   
ACCESSMODES   STORAGECLASS   AGE
voting-prawn-prometheus-alertmanager   Pending                                                     6h
voting-prawn-prometheus-server         Pending                                                     6h
&gt; kubectl get pv
No resources found.
</code></pre>

<h1>Edit 2</h1>

<pre><code>$ kubectl describe pvc voting-prawn-prometheus-alertmanager
Name:          voting-prawn-prometheus-alertmanager
Namespace:     default
StorageClass:
Status:        Pending
Volume:
Labels:        app=prometheus
               chart=prometheus-4.6.9
               component=alertmanager
               heritage=Tiller
               release=voting-prawn
Annotations:   &lt;none&gt;
Capacity:
Access Modes:
Events:
  Type    Reason         Age                From                         Message
  ----    ------         ----               ----                         -------
  Normal  FailedBinding  12s (x10 over 2m)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set

$ kubectl describe pvc voting-prawn-prometheus-server
Name:          voting-prawn-prometheus-server
Namespace:     default
StorageClass:
Status:        Pending
Volume:
Labels:        app=prometheus
               chart=prometheus-4.6.9
               component=server
               heritage=Tiller
               release=voting-prawn
Annotations:   &lt;none&gt;
Capacity:
Access Modes:
Events:
  Type    Reason         Age                From                         Message
  ----    ------         ----               ----                         -------
  Normal  FailedBinding  12s (x14 over 3m)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set
</code></pre>

<p>I had same issues as you.  I found two ways to solve this:</p>

<ul>
<li><p>edit <code>values.yaml</code> under <code>persistentVolumes.enabled=false</code> this will allow you to use <code>emptyDir</code> "this applies to Prometheus-Server and AlertManager"</p></li>
<li><p>If you can't change <code>values.yaml</code> you will have to create the PV before deploying the chart so that the pod can bind to the volume otherwise it will stay in the pending state forever</p></li>
</ul>
