[prev in list] [next in list] [prev in thread] [next in thread] 

List:       opensolaris-docs-discuss
Subject:    Re: [docs-discuss] xntp interval
From:       "Richard L. Hamilton" <rlhamil () smart ! net>
Date:       2008-05-01 6:13:13
Message-ID: 23036731.1209647624031.JavaMail.Twebapp () oss-app1
[Download RAW message or body]

> Ok thank you for the answer:
> 
> I see this value with:
> 
> ntpq> peers  (or with xntpdc>)
> 
> This shows me the poll intervals as seconds  but I
> couldn't able to
> find to change poll interval at /etc/inet/ntp.conf.
> How can I change
> polling intervals in ntpd.conf?
> 
> Regars and thanks in advance.

You probably shouldn't - the defaults are there for a reason - they should
be good enough for anything but extraordinary conditions; lower would
be too much overhead, higher might allow too much drift, and narrower
bounds between minimum and maximum would leave less freedom to adapt
sensibly.

However, I think it _is_ possible if you insist.  Looking at the source, I believe
that xntpd on Solaris is aware of the minpoll X  and maxpoll Y
keywords on the peer and server lines, but for some reason it's not
in the Solaris man page, at least as of Solaris 10.  Some trivial googling
does find it on HP and AIX man pages though.  The number following minpoll
or maxpoll is a power of 2 of the number of seconds.  The minimum allowable
for either value is 4 (16 seconds) and the maximum is 14 (16384 seconds, or
4:33:04 if that's easier to think of).  The minimum must not be greater than
the maximum.  As someone else previously mentioned, the defaults (which
should almost always be good enough) are 6 (64 seconds) and 10
(1024 seconds, which should be 00:17:04), respectively.  Raising the minimum
would probably make it take longer to sync up reliably, although _might_ IMO
make sense in a very flat arrangement with only one level of local NTP server,
to  keep from overloading it; raising the maximum might allow too much drift.
Lowering the minimum would add overhead to servers/peers and the network;
lowering the maximum (to say half, or 512) might make sense with very
unstable clients.  I would be even more reluctant to change the default

I think perhaps the Solaris man page for xntpd might benefit from having those
and any other missing keywords (that the code supports, and that other
implementations document) added to them.   But once again, and as with
things such as /etc/system, going tune-happy is usually _not_ a good idea
unless you're very clear about what problem you're trying to solve, and unless
you _document_ what you've done and why in config file comments or in site
documentation, or both.
 
 
This message posted from opensolaris.org
_______________________________________________
docs-discuss mailing list
docs-discuss@opensolaris.org
[prev in list] [next in list] [prev in thread] [next in thread]