---
title: "Migrate to three scalable targets | Grafana Loki documentation"
description: "Migration guide for moving from two scalable to three scalable targets"
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# Migrate to three scalable targets

> Caution
> 
> Simple Scalable Deployment (SSD) mode is being deprecated and will be removed with the Loki 4.0 release. You should plan to migrate from SSD to microservices or HA monolithic deployment. You will not be able to run Loki 4.0 in SSD mode.

This guide will walk you through migrating from the old, two target, scalable configuration to the new, three target, scalable configuration. This new configuration introduces a `backend` component, and reduces the `read` component to running just a `Querier` and `QueryFrontend`, allowing it to be run as a kubernetes `Deployment` rather than a `StatefulSet`.

**Before you begin:**

We recommend having a Grafana instance available to monitor both the existing and new clusters, to make sure there is no data loss during the migration process. The `loki` chart ships with self-monitoring features, including dashboards. These are useful for monitoring the health of the cluster during migration.

**To Migrate from a “read and write” to a “backend, read and write” deployment**

1. Make sure your deployment is using a new enough version of Loki

This feature landed as an option in the helm chart while still in the `main` branch of Loki. As a result, depending on when you run this migration, you may neeed to manually override the Loki or GEL image being used to one that has the third, `backend` target available. For Loki, add the following to your `values.yaml`.

YAML ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```yaml
loki:
  image:
    repository: "grafana/loki"
    tag: "main-f5fbfab-amd64"
```

For GEL, you’ll need to add:

YAML ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```yaml
enterprise:
  image:
    repository: "grafana/enterprise-logs"
    tag: "main-96f32b9f"
```

1. Set the `legacyReadTarget` flag to false

Set the value `read.legacyReadTarget` to false. In your `values.yaml`, add:

YAML ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```yaml
read:
  legacyReadTarget: false
```

1. Upgrade the helm installation

Run `helm upgrade` on your installation with your updated `values.yaml` file.