menu docs: document MENU SAVE caveat with RAID-1

The usual RAID-1 ADV constraint...

Signed-off-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/doc/menu.txt b/doc/menu.txt
index c912c1d..af93558 100644 (file)
--- a/doc/menu.txt
+++ b/doc/menu.txt
@@ -309,7 +309,12 @@ MENU NOSAVE
        On the other hand, it handles changes in the configuration
        file gracefully.
 
-       The MENU SAVE information can be cleared with
+       NOTE: In software RAID-1 setups MENU SAVE only stores the
+       default label on the actual boot disk.  This may lead to
+       inconsistent reads from the array, or unexpectedly change the
+       default label after array resynchronization or disk failure.
+
+       The MENU SAVE information can be fully cleared with
        "extlinux --reset-adv <bootdir>".
 
        A MENU SAVE or MENU NOSAVE at the top of a (sub)menu affects