external df : t -> string = "ocaml_guestfs_df"
external df_h : t -> string = "ocaml_guestfs_df_h"
external du : t -> string -> int64 = "ocaml_guestfs_du"
external df : t -> string = "ocaml_guestfs_df"
external df_h : t -> string = "ocaml_guestfs_df_h"
external du : t -> string -> int64 = "ocaml_guestfs_du"