vax iso has to become a teeny bit bigger

src/etc/etc.vax/disktab

@@ -1,4 +1,4 @@
-#	$OpenBSD: disktab,v 1.12 2008/02/24 11:47:57 maja Exp $
+#	$OpenBSD: disktab,v 1.13 2009/05/07 17:03:22 deraadt Exp $
 #	$NetBSD: disktab,v 1.2 1996/03/05 12:01:53 ragge Exp $
 #
 #	@(#)disktab	8.1 (Berkeley) 6/9/93
@@ -516,7 +516,7 @@ floppy|floppy3|3in|3.5in High Density Floppy:\
 	:pc#2880:oc#0:
 
 isoroot:\
-	:ty=fake:se#512:nt#11:ns#33:rm#3600:nc#1507:\
-	:pa#547041:oa#0:ba#8192:fa#1024:ta=4.2BSD:\
-	:pc#547041:oc#0:
+	:ty=fake:se#512:nt#11:ns#33:rm#3600:nc#1600:\
+	:pa#580800:oa#0:ba#8192:fa#1024:ta=4.2BSD:\
+	:pc#580800:oc#0: