--- a/sync-to-usb.sh	Fri Feb 17 10:15:51 2012 +0100
+++ b/sync-to-usb.sh	Fri Feb 17 10:43:36 2012 +0100
@@ -96,7 +96,9 @@
 	TYPE=$1
 	CRYPTDEV="cbackup.$TYPE.$$"
 	MOUNTPOINT=$2
-    if mount /dev/mapper/$CRYPTDEV $MOUNTPOINT; then
+	MOUNTOPT=""
+	test "$TYPE" = "source" && MOUNTOPT="--read-only"
+    if mount $MOUNTOPT /dev/mapper/$CRYPTDEV $MOUNTPOINT; then
         debug "OK: [$ME] mount $CRYPTDEV to $MOUNTPOINT"
         [ $LOGGING -eq 1 ] && logger -p local0.notice -t $ME "OK: mount $CRYPTDEV to $MOUNTPOINT"
     else