Be more precise

doc.zih.tu-dresden.de/docs/jobs_and_resources/capella.md

@@ -69,7 +69,9 @@ Although all other [filesystems](../data_lifecycle/workspaces.md)
     Please utilize the new filesystem `cat` as the working filesystem on `Capella`. It has limited
     capacity, so we advise you to only hold hot data on `cat`.
     To transfer input and result data from and to the filesystems `horse` and `walrus`, respectively,
-    you will need to use the [Datamover nodes](../data_transfer/datamover.md).
+    you will need to use the [Datamover nodes](../data_transfer/datamover.md). Regardless of the
+    direction of transfer, you should pack your data into archives (,e.g., using `tar` command)
+    for the transfer.
 
     **Do not** invoke data transfer to the filesystems `horse` and `walrus` from login nodes.
     Both login nodes are part of the cluster. Failures, reboots and other work during the