SUMMARY: Re-adjustment of system time on all workstations

From: Shieh Ping-Lung (
Date: Mon Dec 22 1997 - 14:15:36 CST

I got a number of responses. I want to thank everybody who responded:

  Venu M Middela <>
  Sam Nelson <>
  John Birtley <>
  Daniel Kluge <>
  Matthew Atkinson <>
  Stefan Voss <>
  Rich Kulawiec <>
  Renny Koshy <>
  Nickolai Zeldovich <>
  Ronald Loftin <>
  David Thorburn-Gundlach <>
  Tim Henrion <>
  Scott F. Woods <>
  Paquette, Trevor <>
  Igor Schein <>
  Reto Lichtensteiger <>
  Ayoub, Nicky <>
  Benjamin Cline <>
  Jay Lessert <>
  Steven Sakata <>
  Karl E. Vogel <>
  Eugene Kramer <>
  Jim Harmon <>
  MALLARD, Derek <>
  Bismark Espinoza <bismark@alta.Jpl.Nasa.Gov>
  Joseph S D Yao <>
  K.Ravi <>
  Chris Marble <>

My original post:

> Recently I've encountered problem trying to 'make' files on some of our
> networked workstations. The 'make' command just doesn't see the changes
> made to some of the files immediately and hence refused to make. I've to
> wait for a while and then rerun 'make' so that 'make' command will work
> properly. After some investigation, it turns out that some of our
> workstations have system time much slower than our NFS servers' system
> time. One of the station is even 5 minutes slower!
> What is the best way to re-sync system time on all workstations? Hopefully
> there wouldn't be a need to shutdown/reboot the entire network. We are
> running NIS and mixture of SunOS 4.1.4 and Solaris 2.5.1. Thanks in

There are two solutions to this problem:

1. The simple way is to pick on one machine as the time server and manually
run 'rdate' on other machines so as to sync to the time master. OR, add
the following to the cron on all of the other machines that need to be
synchronized to the time server:

0 * * * * /usr/ucb/rdate timehost >/dev/null 2>&1

Create a DNS/NIS host alias for the selected system that will be the
"timekeeper" and call that alias timehost.

Chris Marble <> pointed out that using 'rdate' to
reset a local clock to another one can lead to the possibility of time
going backwards or a time being skipped (and cron stuf not happening).

2. The other way is to use one of the NTP (Network Time Protocol)
implementations like xntp. xntp can be obtained from or .

Few people pointed out that ntp is shipped with Solaris 2.6.

Once again, thank you all.

Shieh Ping-Lung
Principal Engineer
VLSI Design
Graphics and Video Products
Creative Technology Ltd
31, International Business Park.
Singapore 609921.
Tel: (65)895-4595
Fax: (65)895-4051

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