nixos/docker: warn about changing storageDriver

Add warning to the documentation of
`virtualisation.docker.storageDriver` that changing will cause any
existing containers and images to become inaccessible.

1 files changed, 12 insertions, 2 deletions

diff --git a/nixos/modules/virtualisation/docker.nix b/nixos/modules/virtualisation/docker.nix
index 6fe460316091b..19547a19bcfa9 100644
--- a/nixos/modules/virtualisation/docker.nix
+++ b/nixos/modules/virtualisation/docker.nix
@@ -93,8 +93,18 @@ in
         default = null;
         description =
           lib.mdDoc ''
-            This option determines which Docker storage driver to use. By default
-            it let's docker automatically choose preferred storage driver.
+            This option determines which Docker
+            [storage driver](https://docs.docker.com/storage/storagedriver/select-storage-driver/)
+            to use.
+            By default it lets docker automatically choose the preferred storage
+            driver.
+            However, it is recommended to specify a storage driver explicitly, as
+            docker's default varies over versions.
+
+            ::: {.warning}
+            Changing the storage driver will cause any existing containers
+            and images to become inaccessible.
+            :::
           '';
       };