Want to sycronize the system clock.

[Durvesh Mendhekar]

Hi,

We have the three HP-UNIX 11i servers.
We want to synchronize the clock but these servers are on production so we can not reboot these servers,
So can you please help us how to synchronize the
clocks of these servers.

Regards,
Durvesh M

[Analyst]

Configure NTP.
go for NTP server ,where we can have centralised time for all the machine connected to it.

If it so go for the link.

http://docs.hp.com/en/B2355-90774/ch04.html

[Ganesan R]

Hi Durvesh,

You have to configure NTP to have synchronized time across your system by having one reliabale time source.

There is no manual process to synchronize the time across the servers.

[Ganesan R]

Hi Durvesh,

Here is documnet on how to configure NTP.

http://docs.hp.com/en/B2355-90774/ch04.html

[Durvesh Mendhekar]

Hi,

Thanks for the reply.

I dont want to use any source from which the server get the time.
But i want to synchronize the time of only these three severs as these are the production servers.
So is it possible to synchronize the time of these three servers.

Regards,
Durvesh M

[Jaime Bolanos Rojas.]

Durvesh,

The xntpd daemon can use three different time sources.

1- GSP or radio broadcast.
2- Some NTP servers available on the internet
3- The least reliable a server in your LAN.

So I guess you want to use the third option again. To configure it, please refer to the link that somebody posted above.

Regards,

Jaime.

[OldSchool]

set up ntp, or use xntpd.

pick some server you want to synchronize with. two of the hp servers can sync with the third, or if you've other servers on the network you can use one of them. or they can sync with an outside time source (there are many available public sources)

depending upon your network, there may even be a box already set-up that syncs to an outside clock that you can use.

[Matti_Kurkela]

If the time on the servers is more than 1000 seconds out of sync, the NTP daemon will shut down.

To correct gross errors without shutting down applications, you'll need to use "ntpdate -B" or "date -a". Both will make a gentle adjustment by speeding up or slowing down the machine's idea of time, until the desired amount of adjustment is achieved.

Large corrections will take a while: the maximum speed of adjustment is a bit less than +/- 0.5 seconds per second.

If you can access a NTP timeserver, the "ntpdate -B" command is convenient. For example:
ntpdate -B ntp.server.address

If you cannot access a NTP timeserver, you must use "date -a". You must calculate the necessary adjustment in seconds.

For example, if your system clock is 30 minutes fast, then the necessary correction is -1800 seconds:
date -a -1800

The system clock will then slow down for an hour or so: after the clock has "lost" 1800 seconds, the adjustment is complete and the system clock will automatically resume running in normal speed.

MK

[V. Nyga]

Hi,

just start SAM - then:
Time - NTP Network Tims Sources ->
Actions - AddNTP Server or Peer -> define one server with his name or ip-address -> go.

As said by the others, ntp can't synchronize big gaps between two clocks, you'll have to try.

Volkmar

[OldSchool]

"I dont want to use any source from which the server get the time.
But i want to synchronize the time of only these three severs as these are the production servers.
So is it possible to synchronize the time of these three servers."

you need to have SOME source, but what it is, is up to you. as noted before, you can sync two of the boxes to the third. if you do that, the servers will be "in-sync" with each other, but not necessarily the outside world.

What is the objection to using one of the internet-available time sources, if I may ask?

And for what it's worth, configuring / running NTP does not require reboot, so its "safe" to set up on production machines at any time.

[Durvesh Mendhekar]

Hi,

Thanks for the reply i just wanted to know the alternative if i don't want to use the external source for synchronization.

If it is possible to synchronize the three server without external source then i will try to synchronize them if it will not work then i will look for external source.

Thanks
Regards,
Durvesh M

[OldSchool · Accepted solution]

i got that "i don't want to"....

the question is "Why"...to which you answered "i don't want to"....

which leaves the question unanswered.

Btw: if you've got pc's on your network, they are probably sync'ing there time already. you could probably use that source as well.

and, it's no more difficult to set-up to an outside source than to each other

[Victor Fridyev]

Hi,

Start SAM as recommended previously abd define all these servers as peers. In this case they will be fully syncronized, but their date and time can differ from an current ones. In order to be fully "valid" , allow to one of the machines to use its own clock. As it was mentioned, NTP does not work if time difference is greater than 15 minutes, so don't forget to run ntpdate -b

But if you want to have a valid date/time, you have either to syncronize the machines with an external time server or to use your own internal time source.