topic Re: System Clock in Operating System - HP-UX

System Clock

noe velazquez — Tue, 27 Apr 2010 18:31:14 GMT

Hi my server is a HP-UX B.11.23

I have a problem with the operating system clock. the clock is delayed 15 minutes in a period of 2 months. then I set the clock again and repeat the problem.
Any body know what is the problem?

Re: System Clock

James R. Ferguson — Tue, 27 Apr 2010 18:41:27 GMT

HI:

Fifteen seconds a day is a fairly large amount. Server clocks are not noted for accuracy and a 1-2 seconds drift a day isn't that uncommon depending on the operating environment.

That said, you need to be running NTP (Network Time Protocol) to synchronize your server's time to an accurate source.

For setup, see:

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

For connectivity to free, public, accurate timesources (configure at least three) see:

http://www.pool.ntp.org/en/

Regards!

...JRF...

Re: System Clock

Steven E. Protter — Tue, 27 Apr 2010 19:38:20 GMT

Shalom,

Computer clocks can't tell time.

There is this nifty tool called ntp, which lets you sync your system to a time source. Its already in your 11.23 system.

See /etc/rc.config.d/netdaemons check the xntp settings.

Find a valid time source from your network administrator and this problem will never return.

Note: ntp adjusts to about 16 minutes. Beyond that a manual change will be required to get the system back into that range.

SEP

Re: System Clock

noe velazquez — Tue, 27 Apr 2010 20:52:42 GMT

Thanks for the comments.

This is a production server and the part that I do not understand is all the minutes he has of the other servers carrier delays on other servers only 2 or 3 minutes past due.
1 would have to review some hardware
2 the problem is operating system-level
There will be some other way to solve the problem and that this solution does not use the NTP service.

Re: System Clock

Patrick Wallek — Tue, 27 Apr 2010 22:52:59 GMT

You could open a call with HP support and see what they think.

However, NTP is by far the best solution to keeping time in sync on all servers.

Re: System Clock

rick jones — Tue, 27 Apr 2010 23:52:32 GMT

There are any number of things that cause the "clock" in a computer to run fast or slow - ambient temperature is one, load is another. There clock crystals can vary a bit too. Computers may seem like big, sophisticated, accurate devices, but when it comes to telling accurate time of day they are, without additional steps, inferior to a wristwatch.

As already noted, when someone wants to keep time "in sync" "the" way to do so is to use NTP. The idea is you would point three or more of your systems at willing NTP servers "on the net." Those systems will then be the "root" of your local time tree. You would then point your other servers at those three servers.

Why three? The NTP code has logic in it to separate "good" from "bad" timesources, and it needs/wants at least three timesources to be able to do that.

There will likely be much more in the way of details on www.ntp.org and/or in the HP-UX sysadmin manuals.

Re: System Clock

Raj Briden — Wed, 28 Apr 2010 00:53:17 GMT

Setting NTP is a good idea, Log case with HP for HW support to check the system/iLO MP battery.

Re: System Clock

Kapil Jha — Wed, 28 Apr 2010 02:24:20 GMT

>>This is a production box

this indicate it should have NTP.
what does ntpq -p says.

if you have ntp make sure your source should be running fine, cause you may beat the bush around all the other servers.

Else check the battery on the affected server.

BR,
Kapil+