umount: add note about FS names differences to the man page

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1327209
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/umount.8 b/sys-utils/umount.8
index 2155f2ba52ada1366ac8fe29f4a1ae09b5c34da1..ac22c879d91d2d45b400416d95a74c4eb24a5ea3 100644 (file)
--- a/sys-utils/umount.8
+++ b/sys-utils/umount.8
@@ -138,6 +138,12 @@ More than one type may be specified in a comma-separated list.  The list
 of filesystem types can be prefixed with
 .B no
 to indicate that no action should be taken for all of the mentioned types.
+.BR
+Note that
+.B umount
+reads information about mounted filesystems from kernel (/proc/mounts) and
+filesystem names may be different than filesystem names used in the /etc/fstab
+(e.g. "nfs4" vs. "nfs").
 .TP
 .BR \-v , " \-\-verbose"
 Verbose mode.