diff -up system-config-netboot-0.1.42/diskless/diskless.init.nfs4 system-config-netboot-0.1.42/diskless/diskless.init
--- system-config-netboot-0.1.42/diskless/diskless.init.nfs4	2006-03-05 20:01:54.000000000 +0100
+++ system-config-netboot-0.1.42/diskless/diskless.init	2008-03-21 14:06:16.000000000 +0100
@@ -22,6 +22,9 @@ RETVAL=0
 prog="diskless"
 
 start() {
+        # mount rpc_pipefs for NFS4 idmapd
+        mount -t rpc_pipefs rpc_pipefs /var/lib/nfs/rpc_pipefs &>/dev/null
+
         if [ ! -e /var/lock/subsys/diskless ]; then
 	    umount /.oldroot 2> /dev/NULL
 	    /sbin/blockdev --flushbufs /dev/ram0