Data Domain: EVT-NTP-00001: Network time service is failed

After configuring and enabling NTP service in DD, the NTP service fails:
 

Current Alerts
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Id   Post Time                  Severity   Class         Object               Message                                                         
--   ------------------------   --------   -----------   ---------   ----------------------------------------------
88   Tue Aug 22 13:47:50 2017   ERROR      Environment               EVT-NTP-00001: Network time service is failed.                  
--   ------------------------   --------   -----------   ---------   ----------------------------------------------

The UI reports "The NTP daemon is not running."
The NTP daemon has detected a time difference between this system and the configured network time server (drift) greater than the configured maximum and has shut down.

• The time difference between the Data Domain system and NTP server is too large.
• The NTP server and the DD are in a Different Time zone.
• The gap of the time on client and NTP usually causes the time synchronization failure. 

Caution:  Before going for the resolution of the problem in this section, be aware there is a potential for the DD FS to go down as a result of reenabling NTP in the DD.

See Data Domain: The Data Domain File System (DDFS) may be disabled if there is a backwards jump in system time configured on the system for more details.

If when the NTP server is restarted, local time had already drifted to the future, and hence NTP will bring it back slowly to the right time, for DD6300/DD6800/DD9300 running DDOS 6.x or later there is the risk for the FS to be shut down and stay that way until following the steps in the mentioned KB.

After reading the article linked above, if applicable to the DD model and DDOS version, plan some downtime before making the changes below. Alternatively, make the changes at a time that an unexpected FS shutdown will not affect critical backups.

The steps to make the NTP server to run again are as follows:

• Verify the NTP server Time zone and the current time from the NTP server side.
• Log in to the DDR with admin privileges.
• Check the NTP configuration:        

   # ntp show config
            NTP is currently enabled.
            #    Server
            -     -------------
            1    192.xxx.xxx.xx

• Check the NTP Daemon status:          

   # ntp status
              Status                                     Enabled
              Current Clock Time                         MM DD HH:MM:SS YYYY
              Clock Last Synchronized                    Unknown
              Clock Last Synchronized With Time Server   Unknown
 
            # ntp status
              **** NTP daemon is not running.

• Check the current time in DD:                      

  # system show date

• Check the DD Time Zone:

           # config show timezone
             The Timezone name is: US/Pacific

1. Time Zone Mismatch between NTP server and DD:

There are two ways to resolve this.
Change the DD time zone to the NTP server time zone OR add an NTP server to DD which has the same time zone of DD. 
           
             Resetting time zone:

      # config set timezone Europe/London
        The Timezone name is: Europe/London
        *** You made a change to the timezone setting.  To fully effect this change 
        *** (in currently running processes), you need to reboot the machine.
      # config show timezone
        The Timezone name is: Europe/London

If daylight saving time is observed, use the timezone regional zone names rather than zone name abbreviations or GMT zone names.  Setting the timezone to value such as EST or EDT will result in time jumbs when NTP is configured.

Use US/Eastern, not EST or EDT

            Adding new NTP Server to DD:

             # ntp disable
        # ntp add timeserver <time server list>
          For example: # ntp add timeserver 1.1.1.1 2.2.2.2
        # ntp enable

2. Time Mismatch between NTP server and DD:

• Disable NTP service:

   # ntp disable

• Change DD time as of the NTP server:

        # system set date <MMDDhhmmYYYY>

                   For example to set the system date and time to 0930 on 25th August 2017 the following command would be used:    

 # system set date 082509302017
          **   System date will be adjusted by xxxxxx seconds. This change can
          potentially cause issues for applications running on this system.
          Are you sure? (yes|no|?) [no]: yes
          ok, proceeding.
          Fri Aug  25 09:30:00 GMT 2017

• Enable NTP service:

                    # ntp enable

• Reboot the DD to apply the new timer to the scheduler in DD:

                    # system reboot

After following all the steps above, if the issue is not resolved or if reboot is not possible, contact Dell Support.