expound on async flag

1 files changed, 7 insertions, 4 deletions

diff --git a/sbin/mount/mount.8 b/sbin/mount/mount.8
index 003ad72a172..f2f5b73b55a 100644
--- a/sbin/mount/mount.8
+++ b/sbin/mount/mount.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: mount.8,v 1.14 1999/03/10 02:25:39 pjanzen Exp $
+.\"	$OpenBSD: mount.8,v 1.15 1999/03/24 22:31:09 millert Exp $
 .\"	$NetBSD: mount.8,v 1.11 1995/07/12 06:23:21 cgd Exp $
 .\"
 .\" Copyright (c) 1980, 1989, 1991, 1993
@@ -121,9 +121,12 @@ All
 to the file system should be done asynchronously.
 This is a
 .Em dangerous
-flag to set,
-and should not be used unless you are prepared to recreate the file
-system should your system crash.
+flag to set since it does not guarantee to keep a consistent
+file system structure on the disk.  You should not use this flag
+unless you are prepared to recreate the file system should your
+system crash.  The most common use of this flag is to speed up
+.Xr restore 8
+where it can give a factor of two speed increase.
 .It force
 The same as
 .Fl f ;