[root@localhost src]# showmount -e
Export list for localhost.localdomain:
/export/test1                            simple1*,127.0.0.1,local*,192.168.0.119
/export/aaa                              (everyone)
/export/test4                            (everyone)
/export/exp1                             (everyone)
/export/exp4                             (everyone)
/export/exp1/some/path/exp3              (everyone)
/export/exp1/some/path/exp2/foo/baz/exp5 (everyone)
/export/exp1/some/path/exp2              (everyone)
[root@localhost src]# mount /mnt4
[root@localhost src]# ls /export/exp1
lost+found  some
[root@localhost src]# touch /export/exp1/foo
[root@localhost src]# ln /export/exp1/foo /export/exp1/some/path/exp3
ln: failed to create hard link ‘/export/exp1/some/path/exp3/foo’ => ‘/export/exp1/foo’: Invalid cross-device link
[root@localhost src]# umount /mnt4
[root@localhost src]# mount /mnt4
[root@localhost src]# ln /export/exp1/foo /export/exp1/some/path/exp3
ln: failed to create hard link ‘/export/exp1/some/path/exp3/foo’ => ‘/export/exp1/foo’: Invalid cross-device link
[root@localhost src]# umount /mnt4