Cluster-notes.md

@@ -11,7 +11,18 @@ There is a snippet that can be used to setup a udocker environment on cluster:
 6. exit and enter again inside cluster
 
 ## udocker volume directories
-TODO: dirs creation before volumes mapping
+Normally when you pass a volume to docker it is able to create missing directories related to the passed path. Udocker can not do this, if you write a path inside the [configuration file](configuration-file) and it is not present on disk an exception is raised in which is tell to the user to create all dirs.
+
+Example:
+```ini
+# the configuration file
+[paths]
+dataset = /path/to/my/dataset
+```
+with dataset folder inside /path/to/my does not exist. An error is raised and user can solve it running:
+```bash
+mkdir -p /path/to/my/dataset 
+```
 
 ## udocker no able to build
 TODO: use --development flag to pass code as volume