diff --git a/templates/scripts/includes/deployment.sh b/templates/scripts/includes/deployment.sh
index 3899aae..62eeb0c 100755
--- a/templates/scripts/includes/deployment.sh
+++ b/templates/scripts/includes/deployment.sh
@@ -1347,6 +1347,10 @@ if [ -n "${DATA_PARTITION}" ] ; then
   cat >> "${TARGET}/etc/fstab" << EOF
 ${DATA_PARTITION} /ngcp-data               auto           noatime               0  0
 EOF
+
+  # Make sure /ngcp-data is mounted inside chroot
+  # (some package might need to create folders structure on .postinst)
+  grml-chroot "${TARGET}" mount /ngcp-data
 fi
 
 # provide useable /ngcp-fallback read-only partition
@@ -2079,6 +2083,11 @@ if [[ "${SWRAID}" = "true" ]] ; then
   grml-chroot "$TARGET" update-grub
 fi
 
+# unmount /ngcp-data partition inside chroot (if available)
+if [ -n "${DATA_PARTITION}" ] ; then
+  grml-chroot "${TARGET}" umount /ngcp-data
+fi
+
 # don't leave any mountpoints
 sync