For distributed MinIO deployments, specify the *same* `MINIO_KMS_SECRET_KEY` for each MinIO server process.

At any point in time you can switch from `MINIO_KMS_SECRET_KEY` to a full KMS
deployment. You just need to import the generated key into KES - for example via
the KES CLI once you have successfully setup KES:

```sh
kes key create my-minio-key OSMM+vkKUTCvQs9YL/CVMIMt43HFhkUpqJxTmGl6rYw=
```