ntpd struggling to keep up - how to fix?

[Jeremy Chadwick]

On Sat, Feb 20, 2010 at 10:55:21PM +0100, Torfinn Ingolfsen wrote:
> On Sat, 20 Feb 2010 22:32:01 +0100
> Torfinn Ingolfsen <torfinn.ingolfsen at broadpark.no> wrote:
> 
> 
> This output looks ... wrong ... somehow to my eyes:
> root at kg-f2# date
> Sat Feb 20 22:51:24 CET 2010
> root at kg-f2# ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> *kg-omni1.kg4.no 129.240.64.3     3 u   62   64  377    0.244  597.314 360.123
> root at kg-f2# ntpdc -c loopi -c sysi
> offset:               0.000000 s
> frequency:            500.000 ppm
> poll adjust:          4
> watchdog timer:       549 s
> system peer:          kg-omni1.kg4.no
> system peer mode:     client
> leap indicator:       11
> stratum:              16
> precision:            -18
> root distance:        0.00000 s
> root dispersion:      0.00822 s
> reference ID:         [10.1.10.1]
> reference time:       00000000.00000000  Thu, Feb  7 2036  7:28:16.000
> system flags:         auth monitor ntp kernel stats 
> jitter:               0.360107 s
> stability:            0.000 ppm
> broadcastdelay:       0.003998 s
> authdelay:            0.000000 s
> 
> Shouldn't ntpq and ntpdc be in agreement?

ntpq and ntpdc output data in slightly different formats, depending on
what arguments you give them.  I'm not familiar with the loopi or sysi
commands; Peter should be able to help here.

For sake of example -- look at ntpq's "delay" column for each peer, and
then look at the same column but for ntpdc.  You'll see that for ntpdc
they're divided by 1000 (presumably kern.hz rate):

$ ntpq -c peers
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+clock-a.develoo 204.123.2.72     2 u  476  512  377   25.287   -0.852   0.550
-enigma.wiredgoa 209.81.9.7       2 u  185  512  377   14.754    0.284   0.688
+mtnlion.com     139.78.135.14    2 u  208  512  377   30.788   -0.233   0.160
*ntp1.phoenixpub .LCL.            1 u  179  512  377   36.322   -0.552   0.522
-ntp-1.gw.uiuc.e 128.174.38.133   2 u  141  512  377   77.321   -5.381   0.328
-tick.jrc.us     172.21.0.14      2 u  149  512  377  112.424   -8.110   1.440

$ ntpdc -c peers
     remote           local      st poll reach  delay   offset    disp
=======================================================================
*mailserv1.phoen 192.168.1.51     1  512  377 0.03632 -0.000552 0.09666
=clock-a.develoo 192.168.1.51     2  512  377 0.02528 -0.000852 0.08611
=tick.jrc.us     192.168.1.51     2  512  377 0.11241 -0.008110 0.08615
=enigma.wiredgoa 192.168.1.51     2  512  377 0.01474  0.000284 0.11473
=mtnlion.com     192.168.1.51     2  512  377 0.03078 -0.000233 0.09665
=ntp-1.gw.uiuc.e 192.168.1.51     2  512  377 0.07732 -0.005381 0.10612

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |