Xref: utzoo comp.sys.dec:608 comp.dcom.lans:1175 comp.os.vms:5450
Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!pyramid!decwrl!gidday.dec.com!hirshman
From: hirshman@gidday.dec.com (Bret H., Tech Support @ Sydney, Oz SNE-G 4125546)
Newsgroups: comp.sys.dec,comp.dcom.lans,comp.os.vms
Subject: Re: Time synchronization in a Distributed Environment (>WARNING<)
Message-ID: <8803251624.AA01378@decwrl.dec.com>
Date: 26 Mar 88 10:21:00 GMT
Organization: Digital Equipment Corporation
Lines: 35

A while ago I posted a note making some suggestions about possible methods
for correcting and synchronising the system time on VAXes.  A couple of the
methods involved using the VAX TODR (Time Of Day Register) as a reference.
This is all well and good for *most* VAXes, though I didn't really give enough
information on the VAX/VMS TODR format for any one to use it successfully
without more research.

BUT (and this is a big but, sportsfans!) if you value your system uptime *DON'T*
read the TODR on any of the 85xx/87xx/88xx/89xx series VAXes (the Nautilus
family), and especially don't write to it!  You might corrupt your system time
at best, and hang your VAX at worst.

The reasons for this are too complex to explain here in what is meant to be a
quick warning note.  Suffice it to say that the implementation of the TODR on 
Nautilus-family VAXes is a lot more complex than I led you to believe in my
original posting.  In other words, I blew it.  Sorry about that, folks!

Also, if anybody posted any queries or comments on my original note I'm afraid
I didn't see them.  In the best traditions of Murphy's Law, my news feed went
down for more than a week within hours of my first posting.  Typical! :-)
So please send me mail as well as posting, or just send me mail.  It's a lot
more reliable for me.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                          #      Bret A. Hirshman, Esq.
 "The makers may make     #
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 but the fixers must fix  #  USENET: hirshman@ripper.DEC.COM
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                          #  ARPA INTERNET: hirshman@ripper.DEC.COM
                 Anon.    #  Snail: Digital Equipment Corp. P/L, 18 Glen Street,
                          #         Eastwood, NSW 2122, AUSTRALIA

DISCLAIMER: The above opinions are mine (and probably mine alone, *sigh!*).
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