diff --git a/CHANGELOG b/CHANGELOG
index 7cc6399..da507bb 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,7 +5,7 @@ Revision history for Lufi
 	- Use Weblate instead of Zanata for translations (https://weblate.framasoft.org/projects/lufi/development/)
 	- Add config API endpoint (#183)
 	- Show latest tag and commit of the instance in about page and config API endpoint (#174)
-	- Add support for Swift object storage
+	- Add support for Swift object storage (EXPERIMENTAL)
 
 0.04.6 2019-11-07
 	- Now can send large files (>2Gio) while using a DB other than SQLite (#165)
diff --git a/lib/Lufi.pm b/lib/Lufi.pm
index 832cf31..4f961f3 100644
--- a/lib/Lufi.pm
+++ b/lib/Lufi.pm
@@ -69,6 +69,7 @@ sub startup {
     # Now helpers has been loaded, time to check Swift container
     if ($config->{swift}) {
         $self->check_swift_container();
+        $self->log->info('EXPERIMENTAL Using Swift object storage');
     }
 
     # Recurrent task
diff --git a/lib/Lufi/Command/copyFilesToSwift.pm b/lib/Lufi/Command/copyFilesToSwift.pm
index 91b7564..860538e 100644
--- a/lib/Lufi/Command/copyFilesToSwift.pm
+++ b/lib/Lufi/Command/copyFilesToSwift.pm
@@ -13,6 +13,10 @@ sub run {
         $c->app->check_swift_container();
         my @dirs = glob(File::Spec->catdir($c->app->config('upload_dir'), '*'));
 
+        unless (scalar(@dirs)) {
+            say sprintf('The configured upload_dir (%s) seems to be empty. Is `upload_dir` configured in lufi.conf?', $c->app->config('upload_dir'));
+            exit 1;
+        }
         say sprintf('%d folders to upload to Swift (can\'t say how many files, or the total size, sorry). This can take some time.', scalar(@dirs));
         print 'Do you want to continue? [Y/n] ';
         my $confirm = <STDIN>;
diff --git a/lufi.conf.template b/lufi.conf.template
index e72c890..b7fd9fe 100644
--- a/lufi.conf.template
+++ b/lufi.conf.template
@@ -107,9 +107,14 @@
     # optional, default is 'files'
     #upload_dir => 'files',
 
+    #!!!!!!!!!!!!!!!
+    # EXPERIMENTAL !
+    #!!!!!!!!!!!!!!!
     # You can store files on Swift object storage (https://en.wikipedia.org/wiki/OpenStack#Swift) instead of filesystem
     # Please read https://metacpan.org/pod/Net::OpenStack::Swift#SYNOPSIS to know how to configure this setting
     # IMPORTANT: add a `container` key in it, to let Lufi know which container to use. This is not a regular Net::OpenStack::Swift setting, but Lufi need it.
+    # EXPERIMENTAL: if the upload or download of files are stucked, reload Lufi and create a cron task to reload Lufi once a day
+    # You can copy Lufi files to Swift object storage by launching the command `carton exec script/lufi copyFilesToSwift` (can take a long time)
     # optional, no default
     #swift => {
     #  auth_url    => 'https://auth-endpoint-url/v2.0',