From 39569fd728af6cf22420d0dae3d5c2bed54b44f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Bauer?= <monotek@users.noreply.github.com>
Date: Wed, 19 Feb 2020 23:14:14 +0100
Subject: [PATCH] Update README.md

---
 README.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/README.md b/README.md
index 370f785..dc4073f 100644
--- a/README.md
+++ b/README.md
@@ -40,3 +40,13 @@ Like this, you can add your `docker-compose.prod.yml` to a branch of your Git re
 ## Using Rancher
 
 * RANCHER_URL=http://RANCHER_HOST:8080 rancher-compose --env-file=.env up
+
+## Upgrading
+
+We recently updated the Elasticsearch image from 5.6 to 7.6.
+As there is no direct upgrade path we have to delete all Elasticsearch indicies and rebuild them.
+To do this start docker-compose like:
+
+```
+docker-compose up -e ELASTICSEARCH_PURGE=true
+```