How to increase the size of a persistant volume

All persistant volumes (PV) which are created by the precomposer setup are only created with 1 GiB space. You will probably have to change (increase) this.

For example the elasticsearch PV for Graylog will quickly become to small. We'll use this as an example here.

Prerequisites

You need some kind of administrative access to the cluster:

• Either via UI (your provider's console UI or a kubernetes dashboard)
• or via command line using kubectl
• or login to your ArgoCD instance.

This howto assumes that you are familiar with basic kubernetes handling using one of these methods. So here we only describe what you'll have to do in an abstract way.

Can not be done via GitOps

The creation of persistant volumes during the Precomposer setup is done via volumeClaimTemplates in the corresponding manifests (e.g. epc-deployment-configurations/base/elasticsearch/manifests.yaml) So the values are taken from there (as a template) to create the real persistant volume claims for the PVs. This means that it will not increase the volume by changing the template value in the manifest. You'll have to change the size in the corrrect persistant volume claim (PVC).

Background: The reason why it is done this way (via templates) is to stay independant from the storage providers and even from the storage classes in your environment.

Resizing persistent volumes by changing the persistant volume claims

There are many ways of finding the correct PVC and changing it. Here are some options:

Edit the PVC using kubectl

1. kubectl -n telemetry get pvc will show a list of available PVCs in the namespace "telemetry". It will look similar to this:

   NAME                          STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS       AGE
   es-data-dir-elasticsearch-0   Bound    pvc-1601fd86-d774-498e-a2e8-ec23ecc7e2bc   1Gi        RWO            do-block-storage   65d
   grafana-data-grafana-0        Bound    pvc-6b7f7a0f-c993-4ac7-a518-fd7cb6bbf8a1   1Gi        RWO            do-block-storage   65d
   influxdb-data-influxdb-0      Bound    pvc-f0601dc8-6250-4012-a402-c8e0b08427bb   1Gi        RWO            do-block-storage   65d
   mongo-data-dir-mongodb-0      Bound    pvc-70480c5e-8ea4-40d6-b223-ffe814bc2d09   1Gi        RWO            do-block-storage   65d

2. Change it interactively via kubectl -n telemetry edit pvc es-data-dir-elasticsearch-0 and edit the resource request under spec.

After some minutes the changes will be visible - e.g. by using kubectl -n telemetry get pvc es-data-dir-elasticsearch-0 -o yaml.

Edit the PVC using ArgoCD

1. Log in to ArgoCD - e.g. via https://ops.YOUR_INSTALLATION.precomposer.shop/argo-cd/ (opens in a new tab) (maybe different depending on you installation).
2. Click on the desired application ("logging" in this example).
3. Make sure the full-tree symbol is activated on the top right (first icon).
4. Look for the PVC you want to change ("es-data-dir-elasticsearch-0") and click on it.
5. Scoll below to see the "live manifest".
6. Klick "Edit" and change the resource request under spec.

ArgoCD will update the manifest. It will take some minutes for the changed to become effective.