Moxa DA-681A-I-DPP-T-LX [12/79] Updating the time automatically

DA-681A Series Linux Software Configuration

2-5

Updating the Time Automatically

This section describes how to use a shell script to update the time automatically.

Example shell script for updating the system time periodically

#!/bin/sh

ntpdate time.stdtime.gov.tw

# You can use the time server’s ip address or domain

# name directly. If you use domain name, you must

# enable the domain client on the system by updating

# /etc/resolv.conf file.

hwclock –w

sleep 100

# Updates every 100 seconds. The min. time is 100 seconds.

# Change 100 to a larger number to update RTC less often.

Save the shell script using any file name. For example, fixtime.

How to run the shell script automatically when the kernel boots up

Copy the example shell script fixtime to directory /etc/init.d, and then use chmod 755 fixtime to change

the shell script mode.

moxa@Moxa:~# chmod 755 fixtime

Next, use vi editor to edit the file /etc/inittab.

moxa@Moxa:~# vi /etc/inittab

Add the following line to the bottom of the file:

ntp : 2345 : respawn : /etc/init.d/fixtime

Use the command #init q to re-initialize the kernel.

moxa@Moxa:~# init q

Enabling and Disabling Daemons

Only the following daemons are enabled in the DA-681A by default:

sftpd SFTP Server / Client daemon

sshd Secure Shell Server daemon

You may manage what services to run in the background by the command insserv. Below example shows how

to add the apache daemon in current runlevel.

moxa@Moxa:~$ sudo insserv –d apache2

Apache will not activate in the current boot session, but will be running in the background from the next boot

session. To disable the apache daemon, use the following command:

moxa@Moxa:~$ sudo insserv -r apache2