Augment ino64 entry

When updating across this change (the introduction of ino64), the
"fast and loose" practice of rebooting to multiuser and then doing an
installworld fails with missing symbols. Recommend strongly that users
do this in single user mode. The multiuser case only ever works by
accident because its requirements are stronger than is supported
accross this change. It usually works because critical symbols don't
change their version number in libc, which wasn't the case here.

1 files changed, 7 insertions, 5 deletions

diff --git a/UPDATING b/UPDATING
index 871176a70be3..bb8ddc6c04e5 100644
--- a/UPDATING
+++ b/UPDATING
@@ -714,11 +714,13 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 13.x IS SLOW:
 	system will be running the ino64 kernel with the existing world).
 
 	For the safest in-place upgrade begin by removing previous build
-	artifacts via "rm -rf /usr/obj/*".   Then, carefully follow the
-	full procedure documented below under the heading "To rebuild
-	everything and install it on the current system."  Specifically,
-	a reboot is required after installing the new kernel before
-	installing world.
+	artifacts via "rm -rf /usr/obj/*".  Then, carefully follow the full
+	procedure documented below under the heading "To rebuild everything and
+	install it on the current system."  Specifically, a reboot is required
+	after installing the new kernel before installing world. While an
+	installworld normally works by accident from multiuser after rebooting
+	the proper kernel, there are many cases where this will fail across this
+	upgrade and installworld from single user is required.
 
 20170424:
 	The NATM framework including the en(4), fatm(4), hatm(4), and