diff --git a/xCAT-genesis-scripts/debian/postinst b/xCAT-genesis-scripts/debian/postinst
index f5e28d707..55a4d98bb 100644
--- a/xCAT-genesis-scripts/debian/postinst
+++ b/xCAT-genesis-scripts/debian/postinst
@@ -20,6 +20,7 @@ set -e
 
 case "$1" in
     configure)
+    echo "If you are installing/updating xCAT-genesis-base separately, not as part of installing/updating all of xCAT, run 'mknb <arch> manually'"
     touch /etc/xcat/genesis-scripts-updated
     ;;
 
diff --git a/xCAT-server/lib/xcat/plugins/mknb.pm b/xCAT-server/lib/xcat/plugins/mknb.pm
index e4cd41283..4bae8272b 100644
--- a/xCAT-server/lib/xcat/plugins/mknb.pm
+++ b/xCAT-server/lib/xcat/plugins/mknb.pm
@@ -53,6 +53,9 @@ sub process_request {
    if (! $arch) {
       $callback->({error=>"Need to specify architecture (x86, x86_64 or ppc64)"},{errorcode=>[1]});
       return;
+   } elsif ( $arch eq "ppc64le" or $arch eq "ppc64el" ) {
+       $callback->({data=>"The arch:$arch is not supported at present, pls use \"ppc64\" instead"});
+       return;
    }
    unless (-d "$::XCATROOT/share/xcat/netboot/$arch" or -d "$::XCATROOT/share/xcat/netboot/genesis/$arch") {
       $callback->({error=>"Unable to find directory $::XCATROOT/share/xcat/netboot/$arch or $::XCATROOT/share/xcat/netboot/genesis/$arch",errorcode=>[1]});