Greetings;

I think this subject has gone around several times already.

The VM time server is only a solution as long as you are isolated
from the Rest Of the World. When you start talking to systems outside
your LAN you really should be synching all of your system clocks
to UTC (See: http://www.time.gov/about.html ) This makes it much easier
to troubleshoot related events. From experience, as little as 9 seconds
difference in time makes troubleshooting difficult, 90 secs can make it
impossible!

I think this is a necessary addition to the S/390; the ability to set the
system clock programatically without having to IPL and not having to
manually
enable the operation. I know there are clever ways to do this by
manipulating
the time zone in VM but that really isn't a practical solution. The time
needs
to be checked frequently and adjusted as needed so all systems are as close
to
being on the same tick as possible. The software for doing this has been
available for PCs and other HW for quite some time and could probably be
quickly
ported to z/VM and z/OS if the mechanical problem were out of the way.

Good Luck!
Dennis







Aria Bamdad <[EMAIL PROTECTED]> on 01/14/2002 08:07:24 AM

Please respond to Linux on 390 Port <[EMAIL PROTECTED]>

To:   [EMAIL PROTECTED]
cc:    (bcc: Dennis Wicks/infosvcs/CDG)
Subject:  Re: VM and Linux time of day





On Fri, 11 Jan 2002 17:02:16 -0600 Dennis G. Wicks said:
>Greetings;
>
>Linux will set its clock like any well behaved system. If you can and
>want to you can set up the usual ntp (Network Time Protocol) functions
>and synchronize your linux machines time to the rest of the world. This
>requires internet access, which is where the "can" comes in. Or you can
>get the time from a time server on your lan.
>
>Unfortunately, VM and OS can't do this yet. Unless something has been
>quietly added in z/VM. I think there is a time server available, but I
>haven't investigated it.
>

There is a time server available for VM.  It is free to download at the
VM web site www.vm.ibm.com under the download directory.   I have been
using it to set the time on other systems at my organization and it works
well.

Aria




>As for the difference between your VM host and the linux guest there are
>many possibilities. Choose whether to synchronize to VM or to ROW,
>use a date command to set your linux clock and be happy! ;-)
>
>Good Luck!
>Dennis
>
>
>
>
>
>Jean Bedard <[EMAIL PROTECTED]> on 01/11/2002 03:16:46 PM
>
>Please respond to Linux on 390 Port <[EMAIL PROTECTED]>
>
>To:   [EMAIL PROTECTED]
>cc:    (bcc: Dennis Wicks/infosvcs/CDG)
>Subject:  VM and Linux time of day
>
>
>
>
>
>Hi,
>
>I'm a bit confused here. I thought Linux (SuSE Linux in this case) took
the
>date and time from VM (or from the hardware), but now I realize that on my
>zVM 4.2 system, CP QUERY TIME is currently about 90 seconds ahead of the
>results of the Linux "date" command. How can it be?
>--
>* Jean Bedard
>* VM System Manager             S.I.T., Universite Laval
>* [EMAIL PROTECTED]     (418) 656-2131 ext. 4014

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