Secured parallel mirroring using lftp.

backup-ftp.sh

#!/bin/bash

if (( $# != 3 )); then
    echo "Usage: $0 ftp.example.com ftp-user ftp-password"
    exit 1
fi

SERVER=$1
USER=$2
PASS=$3
TARGET="./$2@$1/"

mkdir -p $TARGET

lftp <<EOF
set ftp:ssl-force true
#set ssl:verify-certificate false
set mirror:parallel-directories yes
set mirror:parallel-transfer-count 8
set mirror:skip-noaccess yes
set ftp:list-options -a
connect $SERVER
user $USER $PASS
mirror / $TARGET
quit
EOF