I was performing a nas_checkup on the new system I just installed and found this warning:

————Warnings———————

Blades : Check connectivity to NTP servers

Warning HC_DM_18800115743:

* server_2: Only one NTP server is configured. It is recommended to define at least two different NTP servers for a high availability.

If the clock of the Data Mover is not correct, potential errors during Kerberos authentication may happen (timeskew).

Action : Use the server_date command to define another NTP server on the Data Mover. Read the man pages for details and examples.

——————————————

So I must have missed the configuration of the second NTP server, but no problem because there is a procedure for that, right? So this is what happened next:

1. Login into the Unisphere, click on the Home Icon and then of the Domains Tab

2. On the right column click the Configure NTP link

3. Click OK in the Pop-Up Warning Window, and then you can edit you NTP settings, in my case in fact I had only one NTP server defined, so I added the second one

4. I executed the nas_checkup again, but I still had the same warning. If you log into the control station with ssh user nasadmin, then you can check the NTP status with this command:

[nasadmin@cs0 tools]$ server_date server_2 timesvc stats ntp
server_2 :
Time synchronization statistics since start:
hits= 45, misses= 0, first poll hit= 2, miss= 0
Last offset: 0 secs, 0 usecs
Current State: Running, connected, interval= 60
Time sync hosts:
10.1.3.10,

See above in bold that only the first NTP server appears in the output, I also tried to stop and start the NTP service, I logged as root and executed the /sbin/service ntpd [stop/start], but the system still reported one NTP server and I still had my warning message.

5. Resolution: I stopped the ntp service and then started it again with both hosts included in the command line.

[nasadmin@cs0 tools]$ server_date server_2 timesvc stop ntp
server_2 : done
[nasadmin@cs0 tools]$ server_date server_2 timesvc start ntp 10.2.3.10 10.1.3.10
server_2 : done
[nasadmin@cs0 tools]$ server_date server_2 timesvc stats ntp
server_2 :
Time synchronization statistics since start:
hits= 1, misses= 0, first poll hit= 1, miss= 0
Last offset: 0 secs, 51 usecs
Current State: Running, connected, interval= 60
Time sync hosts:
10.2.3.10, 10.1.3.10,
[nasadmin@cs0 tools]$

…

Blades         : Checking connectivity to NTP servers…………………. Pass

And I will be able to sleep tonight.