diff --git a/docker/README.md b/docker/README.md
--- a/docker/README.md
+++ b/docker/README.md
@@ -584,6 +584,61 @@
   (swh) ~/swh-environment$ swh scheduler task respawn 1
 ```
 
+## Data persistence for a development setting
+
+The default docker-compose.yml configuration is not geared towards data persistence,
+but application testing.
+
+Volumes defined in associated images are anonymous and may get either unused or removed.
+Docker and docker-compose documentatioms are not clear about their behavior regarding
+anonymous volumes.
+
+One way to make sure these volume persist is to use named external volumes, created beforehand.
+To use vanilla named volumes, fully managed by Docker, create them like this:
+
+```
+for vn in swh-storage-data swh-objstorage-data;
+do
+    docker volume create "${vn}"
+done
+```
+
+We can also create them as named host volumes so that the data is also accessible
+like a non-containerized service (which is not portable). Common considerations
+about file ownership and permission apply. Data should be accesible to the user
+in the container.
+
+```
+for vn in swh-storage-data swh-objstorage-data;
+do
+    sudo mkdir "/data/docker/${vn}";
+    sudo chown 1000:docker "/data/docker/${vn}"; # 1000 is the uid of "swh" user in the containers
+    docker volume create -d local --opt type=none --opt o=bind --opt device="/data/docker/${vn}" "${vn}"
+done
+```
+
+Then, the volumes may be defined this way in the docker-compose.yml:
+
+```
+services:
+  swh-storage-db:
+    image: postgres:12
+    volumes:
+      - "swh_storage_data:/var/lib/postgresql/data"
+  swh-objstorage:
+    image: swh/stack
+    volumes:
+      - "objstorage_data:/srv/softwareheritage/objects"
+
+volumes:
+  swh_storage_data:
+    external: true
+  swh_objstorage_data:
+    external: true
+```
+
+This way, `docker-compose down -v` will not remove those volumes along with the
+anonymous ones, only `docker volume rm` will.
 
 ## Starting a kafka-powered mirror of the storage