Mac OS X 10.5 Leopard: Installing on a UFS-formatted volume. Apple, 12. Juni 2012, abgerufen am 28. März 2020 (englisch): „You cannot install Mac OS X Leopard on a UFS-formatted volume. In addition, you cannot upgrade older versions of Mac OS X installed on UFS-formatted volumes to Leopard. To upgrade to Leopard you need to reformat your startup volume.“