Have you installed Unidata LDM on a Redhat 7 or CentOS 7 machine (or other system with systemd)? Well here is a script you can add to systemd to start on boot. This assumes your ldm is installed in /usr/local/ldm and the user is ldm

Just create a file in /etc/systemd/system called ldm.service and add it to systemd with
systemctl add ldm

You can setup autostart and turn LDM on by issuing
systemctl enable –now ldm

[Unit]
 Description=Unidata Local Data Manager
 After=network.target
 [Service]
 Type=forking
 ExecStartPre=/usr/local/ldm/bin/ldmadmin delqueue
 ExecStartPre=/usr/local/ldm/bin/ldmadmin mkqueue
 ExecStart=/usr/local/ldm/bin/ldmadmin start
 ExecStop=/usr/local/ldm/bin/ldmadmin stop
 PIDFile=/usr/local/ldm/ldmd.pid
 Restart=on-failure
 SuccessExitStatus=1
 User=ldm
 [Install]
 WantedBy=multi-user.target