d-i partman-auto/expert_recipe string                         \
      boot-root ::                                            \
              40 50 100 ext3                                  \
                      $primary{ } $bootable{ }                \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext3 }    \
                      mountpoint{ /boot }                     \
              .                                               \
              2000 3000 5000 ext3                             \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext3 }    \
                      mountpoint{ / }                         \
              .                                               \
              10000 15000 20000 ext3                          \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext3 }    \
                      mountpoint{ /extra }                    \
              .                                               \
              64 512 100% linux-swap                          \
                      method{ swap } format{ }                \
              .