> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dcdeploy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Persistent Volumes

> Use persistent volumes in DCDeploy to store data that survives container restarts, deployments, and scaling operations.

## Overview

By default, workloads in DCDeploy use **ephemeral storage** — data is lost when the container restarts, redeploys, or scales.\
To store data reliably across restarts and deployments, DCDeploy provides **Persistent Volumes**.

Persistent volumes are ideal for databases, file storage, or any workload that needs durable storage.

***

## Use Cases

* Running databases like **Postgres, MySQL, MongoDB**.
* Storing **uploaded files** (images, PDFs, media).
* Maintaining **caches, logs, or stateful services** that must survive restarts.

***

## Prerequisites

* An active **environment** in DCDeploy.
* A workload with volume support enabled.
* Sufficient quota for storage (allocated at org level).

***

## Step-by-Step Guide

### 1. Create a Service with Volume

In the **DCDeploy dashboard**:

1. Go to **Deploy → Add Service**.
2. Under **Workload Settings**, choose **Persistent Volume**.
3. Set the **volume size** (e.g., 10GB).
4. Mount it at a path inside the container (e.g., `/data`).

Example YAML (`DCDeploy.yml`):

```yaml theme={null}
services:
  my-db:
    image: postgres:15
    volumes:
      - mountPath: /var/lib/postgresql/data
        size: 20GB
```

### 2. Access the Volume

Inside your container, the mounted path behaves like a local folder.
Example (Postgres):

```bash theme={null}
psql -h localhost -U user -d mydb
# Data will persist in /var/lib/postgresql/data across restarts
```

### 3. Scaling Behavior

* Vertical scaling (CPU/RAM changes): volume is preserved.
* Horizontal scaling (multiple instances): each instance gets its own volume (data is not automatically shared).
* For shared storage, use an external database or object storage.

## Best Practices

* Always mount databases to a persistent volume.
* Avoid storing large assets directly in volumes; use object storage (S3, GCS) instead.
* Use backup tools to periodically snapshot data.
* Keep volumes lightweight for faster redeploys.

## Troubleshooting

* Data loss after redeploy: Ensure you’re using a persistent volume, not ephemeral storage.
* Multiple replicas with inconsistent data: Volumes are not shared — use an external DB if consistency is required.
* Storage full errors: Increase the volume size via dashboard or update your DCDeploy.yml.