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

Clock time

M. Tariq Ayub — Sat, 25 Oct 2003 23:23:50 GMT

Hi All,

I have a Peculiar problem. I have six HP9000 server of which 2 are rp8400 and 4 rp5470. I have synchronized all the servers time on 21-Oct-03. Today i foud that 8400 are giving the same time ( as in my source clock ) but 4 rp5470 are same time but 4 sec less than 8400.
I am not using any NTP or external time source.

How come this happen. Any one had any idea.

Re: Clock time

Rajeev Shukla — Sun, 26 Oct 2003 01:15:44 GMT

How much ever time you syncronize the times between the systems you'll always have time drifts. And its true for all kind of systems.
That is the reason why one should use NTP to keep track of the drifts in the time and let them syncronize themselves.
I encourage you to use to either use you'r routers or some external time source to syncronize the time using NTP.

Re: Clock time

Steven E. Protter — Sun, 26 Oct 2003 01:44:48 GMT

HP-9000 server clocks are notoriously inaccurate. I have one that gains 15 minutes a month.

I mitigate this with ntp. Thats the best way to go.

SEP

Re: Clock time

A. Clay Stephenson — Sun, 26 Oct 2003 14:44:59 GMT

Hp makes good computers but they are lousy clocks. Your drift is typical and reasonable. You should always use NTP to keep time sync'ed on UNIX boxes. Even if you don't use NTP to sync to an external source, you should at least use NTP to sync them to the same source. That way, if they are wrong, they are at least all wrong together.

Re: Clock time

John Waller — Mon, 27 Oct 2003 12:31:16 GMT

This 4 seconds in 6 days sounds reasonable. We had a problem on an a A400 where it lost 15 seconds per hour, but that turned out to be a problem with an incorrect jumper setting on the motherboard. I agree with everyone else in that I would setup one of the 8400 as an ntp server and the 5470's as clients.

Re: Clock time

Hemanth Gurunath Basrur — Mon, 27 Oct 2003 12:35:06 GMT

Hello Tariq,

Refer to this doc for info.

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/J2771-90010/J2771-90010_top.html&con=/hpux/onlinedocs/J2771-90010/00/00/73-con.html&toc=/hpux/onlinedocs/J2771-90010/00/00/73-toc.html&searchterms=time%7cin%7cmilliseconds%7csystem&queryid=20031027-103032

HTH.

Regards,
Hemanth

Re: Clock time

Todd McDaniel_1 — Mon, 27 Oct 2003 12:52:17 GMT

I would heartily suggest getting NTP loaded... it is a boon for those of us that need precise timing.

managing time by hand can be hazardous... I might suggest creating a CRON to capture date from one host and sync time with all boxes...

Using "remsh date" will give you the date on another host if you utilize .rhosts on all boxes involved. Then it is a simple matter of capturing the output and scripting the new date for the other boxes with the date command.

You can use the "-a [-]sss[.fff]" option to gradually change the time to sync, if there is a great disparity b/t the times on different hosts.