> I tried breaking the hosts up into three equal sized blocks (say, pool1,
> pool2, and pool3 for example). and found that if I listed all three pools in
> the ntpd directive. i.e.:
...
> To my surprise, I got an even distribution of nodes from each of the defined
> pools (X is for anonymity):
Harlan said:
> We're open to doing an even better job of telling folks about things like
> this.
I think a message should go out to (almost?) all lists when security fixes
are available to the general public.
The first mail on questions was David Taylor's announcement of the
availability of
> Third, in my reading of the source code for the Network Time Protocol Daemon
> (NTPD), the program is optimized to handle a high number of requests per
> second, not to record who is making the requests.
Look at the mrulist. You can see it from ntpq
ntpq -c mrulist
The default size is 600
> By the way, the code I am writing is not part of a NTP algorithm to adjust a
> system clock for time. It is for a one-time frequency calibration of an
> oscillator. I take a time snapshot at the beginning and at the end of an
> approximately six hour period during which I am counting cycles
> The Sure device works, but for me it was too difficult to make the PPS work.
> I bought two and was unable to make either one output a detectable PPS. The
> PPS was there, my scope told me so, but I could not make the computer detect
> it. On the other hand, I am very clumsy, and have little
folk...@vanheusden.com said:
> How can I tell NTPd that an SHM time source is actually a PPS and that it
> thus should combine it with some other sources? (an '*' + 'o' combination so
> to say)
I don't think you can do it the way you have described.
The API for SHM requires that you have
elliott...@comcast.net said:
> Thank you very much for the paper reference on temperature compensation. The
> paper and its results are excellent. A self-calibration feature (that
> worked) so that each user could have it configured for his/her own computer
> should not be too hard to implement.
> I thought of that too but rejected it as way too machine-specific. Because
> the clock PLL does not track frequency ramps feed-forward could be very
> effective (e.g. order of magnitude). To make this work however, you need to
> first discover which one of many potential temperature sensors
> Is there a generally accepted NMEA ?best sentence? for use with ntp? For
> example, I?ve seen GPRMC, GPGGA and GPZDA all individually recommended in
> Google searches, variously at 4800 or 9600 baud. Will whatever sentence I
> choose ultimately give the same results?
Do you have a specific
> But something is not working as I'm expected that. In the rawstats and
> peerstats I can see just the time of the ntp servers from which I'm syncing,
> but I don't see the time of clients who are syncing from me.
> It's very strange, because according to the docs: rawstats : Each NTP packet
>
> * I was accepting that once ntp server (1) will have reach value=0,
> the tally code (*) will be removed, and orphan mode will be available
How long did you wait? It might take 5 or 15 minutes to give up on the old
server.
--
These are my opinions. I hate spam.
>> I'm assuming your TCXO is driving your A/D.
> Yes. It spits out samples at a rate f_osc / 24 = 60 Hz. My ultimate
> task is to timestamp these samples in such a way that there are compressions
> and dilations in the time scale, but no discontinuities.
60 Hz is pretty slow. The PPS
m...@hau.nz said:
> The A/D is a sigma-delta type where you set the output sample rate and it
> runs autonomously (locked to the input clock of course). "Sample ready" is
> indicated by a falling edge on the SPI MISO line, and I am bitbanging the
> serial interface from the PRU ...
I'd expect
> I would like the data stream from my A/D to be long-term accurate. That is,
> if the sampling rate is 60 Hz, I would like 60*86400*365 +/- 1 samples in a
> [non leap] year.
> To that end, I'd like to discipline the TCXO using ntpd. I would like it to
> *not* change the virtual clock
>>http://users.megapathdsl.net/~hmurray/ntp/GPS18LVCx-off.gif
> You must have had one of the bad firmware releases: David Taylor's site
> shows the improvement he got after upgrading to better firmware releases, in
> which I believe you were involved with "Kiwi" Geoff on analysis.
>
> Garmin is a real GPS. please don?t mock me...
The timing on the GPS-18x is also horrible. The GPS-18 (no x) was good, but
it wasn't very sensitive.
http://users.megapathdsl.net/~hmurray/ntp/GPS18LVCx-off.gif
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[SiRF wander.]
> Ugh! I would not have expected that much variation over USB - WiFi does
> better!
It's not USB. It's a firmware "feature".
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___
questions mailing list
questions@lists.ntp.org
> i would like to set up an ntp-server thats does not give back the correct
> utc time, but for example utc-1 or another "wrong" time computed before.
> Until now the only way I reached that result was to set the local clock to
> the wished time and to sychronize then with 127.127.1.1.
If you
sandip gangakhedkar said:
> Let me clarify that the two nodes *do not* have access to the internet, but
> only to each other, over an unreliable wireless link. So I did not consider
> the option of choosing NTP sync during the measurements.
What sort of distance accuracy are you expecting?
What
Re. the Fitlet: With a 3.9 to 4.5 W power budget this box will never get
into those ranges, but even handling 1K requests/second with sub-ms jitter
and delay would still be a very nice Pool server.
A Raspberry PI can do 1500 packets per second.
That's a simple measurement with one request
Is there a reasonable HOWTO type document describing how to set things up?
Several years ago, Dave announced that one of the machines at UDel was ready
for testers. I got as far as discovering that Autokey doesn't work through
NAT boxes. Since I'm behind a NAT box, I gave up.
I should be
[Context is google-smear.]
For distributed logging you have to use the same method for every single
node, but that is the case today as well. :-(
I.e. with one domain smearing and another stepping, the times between them
will be skewed over the entire smearing period.
How often do people
Just a heads-up in case you hit this, or want to avoid it.
The symptom is BUG: scheduling while atomic
https://bugzilla.redhat.com/show_bug.cgi?id=1065087
The discussion at
https://lkml.org/lkml/2014/2/18/77
confirms that it's the low-latency path that is buggy.
My setup works fine under
In article jf4tou$7rf$1...@dont-email.me,
unruh un...@invalid.ca writes:
How do I enable kernel pps? I have kernel 2.6.33-7mdb (Mandriva 2010.1)
which has a pps_core module. But even if I install that module I get no
/dev/pps0 device not a /sys/class/pps/pps0
Somehow I have to tell it to use
In article 95325d10-3ee0-482e-927f-53991e056...@v5g2000vbh.googlegroups.com,
jimmyterrence jimmyterre...@gmail.com writes:
What do I need to do to get ntp to notice the PPS signal? What am I
missing?
You need to do something like:
ldattach 18 /dev/gps0
That will create /dev/pps0
Beware: If
In article slrnj9ph83.sve.un...@wormhole.physics.ubc.ca,
unruh un...@physics.ubc.ca writes:
On 2011-10-17, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
In article slrnj9oqdj.3i3.un...@wormhole.physics.ubc.ca,
unruh un...@physics.ubc.ca writes:
In fact it is really hard
In article pine.lnx.4.64.1110161231540.14...@info.physics.ubc.ca,
Bill Unruh un...@physics.ubc.ca writes:
fine. Otherwise I have never used trimble proprietary language so have no
idea what driver to use.
There is a driver that covers the Trimble Palisade and Thunderbolt.
If you are lucky,
In article slrnj9oqdj.3i3.un...@wormhole.physics.ubc.ca,
unruh un...@physics.ubc.ca writes:
In fact it is really hard for a computer to keep to 1us accuracy because
of the delays in interrupt processing.
It's not the delay that is the problem. It's simple to correct for a
fixed delay. (at
In article j5q79m$2u8$1...@dont-email.me,
David Woolley david@ex.djwhome.demon.invalid writes:
Miguel Gon=E7alves wrote:
What is a typical offset of the loop without using special oscillators?
Is less than 1 us achievable?
Depends on the network or reference clock, and the resolution to which
$GPZDA ?
I tried it on one unit. It didn't help. If anybody has examples of
it working please let us know what type of GPS receiver you tested.
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questions mailing list
The problem is that the adjustment takes to large steps, not that it
takes to long time.
ntpd will slew the clock at 500 PPM. You may be willing to wait a while
for a second or two, but it takes a long time if you have to adjust
by several minutes or an hour. That may be OK for your setup,
The following is an example from ntpd.log
14 Apr 07:22:25 ntpd[1048]: synchronized to 10.0.0.5, stratum 1
14 Apr 07:22:25 ntpd[1048]: time reset +0.231004 s
14 Apr 07:23:35 ntpd[1048]: synchronized to 10.0.0.5, stratum 1
14 Apr 07:39:33 ntpd[1048]: time reset +0.318457 s
14 Apr 07:39:33
In article 51c20190-11b8-4629-a762-cbf95369e...@r18g2000vbs.googlegroups.com,
Eugen COCA ec...@eed.usv.ro writes:
Due to a network problem on our provider, the packets were routed on a
different path than usual yesterday, for several hours. This period,
NTP displayed wrong offsets:
ntpd assumes
In article banlktikc4ydiycbw4no2ay2o-r+dfp9...@mail.gmail.com,
steven Sommars stevesommars...@gmail.com writes:
You may want to watch for several days. Previous 18x LVC firmware (3.60)
drifted on my system from 0.5 to 1.4 seconds over a span of 6 days. I've
been running a beta version of 3.70
In article 35fcd513-e8ea-4feb-a33b-6d47d6556...@mac.com,
Chuck Swiger cswi...@mac.com writes:
On May 19, 2011, at 10:01 AM, M. Giertzsch wrote:
To run into the problem that the client is not syncing to the server I
-- stopped the NTP service on both client and server
-- changed the time on the
[default pool command uses 10 servers]
I agree. It is absurd. It seems to indicate that the ntp folk really
really do not trust the pool, and figure that if you get fewer than 10, you
have a
reasonable chance that a majority will deliver bad time. Ie, they appear
to feel that the pool is a
In article slrnir4ti8.j3t.un...@wormhole.physics.ubc.ca,
unruh un...@wormhole.physics.ubc.ca writes:
On 2011-04-23, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
All it takes is a firmware bug and to have several NTP servers
using the same GPS device with the bug.
What good
Consider that failure here encompasses serves bogus time. Suppose
you have 7 sources configured and 4 of them cluster nicely around an
incorrect time, with 3 clustered around UTC.
I suppose it's possible but I'm not going to hold my breath waiting for
an instance to appear!
All it takes is
I would have hoped that the pool folk kept their documentation up-to-date,
so I'll post that on their list. You didn't mention how to control the
number of servers uses - is it just multiple pool entries?
You only need one pool command.
pool server-name
will use as many addresses from
In article iof9dn$alt$1...@speranza.aioe.org,
Edward T. Mischanko etm1...@hotmail.com writes:
ntpq 4.2.7p153 only shows 5 peers when many more are configured?
server 127.127.20.0 minpoll 3 maxpoll 3 prefer
fudge 127.127.20.0 time2 0.800 refid PPS flag1 1 flag3 1
server tick.cerias.purdue.edu
In article hiUjp.6071$yl2.1...@newsfe07.iad,
Bruce Lilly bruce.li...@gmail.com writes:
Mutexes can work across processes; look for pthread_mutexattr_setpshared.
Thanks.
The first party who needs the mutex (if not already initialized)
initializes it. Destruction is another issue.
How do I
In article 4da0c50f.3050...@comcast.net,
Richard B. Gilbert rgilber...@comcast.net writes:
On 4/9/2011 12:55 PM, Hal Murray wrote:
Is there any way to test to see if a mutex has been initialized?
You initialize your mutex BEFORE it is needed.
Right. But consider the case of ntpd and gpsd
The clock puts out all of its signals on BNC. I'm not clear on the
nomral assumptions with such wiring; for example, does one normally
connect everything with BNC-T's, with the first and last T terminated
with a 50ohm resister, or should I just connect direct through?
It's audio you don't
In article slrnionrs2.teh.koste...@stasis.kostecke.net,
Steve Kostecke koste...@ntp.org writes:
On 2011-03-24, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
Yes. The encryption also verifies that you are talking to the
server you think you are talking to rather than an imposter
In article ghps58-1a@mail.specsol.com,
j...@specsol.spam.sux.com writes:
When I see questions like this my first response is Why all the bother?.
There is nothing secret or proprietary about the time of day.
Since all NTP servers provide UTC, the service reveals nothing about the
machine
oh, come off it. Your reaction time is nowhere near what ntp -q would
give you. Using ntp -q run once every hour, and assuming say a 20PPM
drift for the crystal, his clock would be out by less than a 100 ms due to
the
drifting, and your reaction time with your watch ( and wyour watch) are
You can probably do better than that. That is for the reaction to
something that you do not expect. Ie, you have decide that the event has
occured and then send the messages to your finger to press. However for
the timing, you know exactly when it is going to occur. You can get
yourself into a
In article 2wlgp.34776$d46.31...@newsfe07.iad,
Bruce Lilly bruce.li...@gmail.com writes:
o POSIX mutex for synchronized access to shared memory for updates
-- obviates mode 0 / mode 1 / OLDWAY
I'm far from a POSIX wizard. When I google for POSIX mutex I get
a bunch of hits that all are
In article Xns9E95DA199C4695r68mtnbtdvsdr@194.109.133.242,
Maarten Deen zq...@kf4nyy.ay writes:
...
23 Feb 20:42:53 ntpd[27664]: time reset +2.421296 s
23 Feb 20:52:05 ntpd[27664]: synchronized to 217.67.231.25, stratum 2
23 Feb 20:58:31 ntpd[27664]: time reset +2.356457 s
23 Feb 21:04:48
In article ia4v28-a6c@p4x2400c.home.lordynet.org,
David Lord sn...@lordynet.org writes:
or even a LED + diode + resistor will be enough to show if there is
a pulse. Radioclkd2 can be used in debug mode to confirm the single
DCD pulse and width.
Some devices put out a narrow (10 microsecond)
In article slrnilckj1.3pd.nom...@xs8.xs4all.nl,
Rob nom...@example.com writes:
Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
It would be good if someone (or someones) has actually been collecting
rawstats for a long period, to serve as a baseline. Bufferbloat is a
relatively new
In article ijhd7d$au6$1...@news.eternal-september.org,
E-Mail Sent to this address will be added to the BlackLists
Null@BlackList.Anitech-Systems.invalid writes:
As far as I can tell the products have all the knobs
they need to be properly configured to deal with the issue.
The ISPs /
In article aanlktimlss1bjtrde77av92-wwfyr_g7ovm7zd0yr...@mail.gmail.com,
Chris Albertson albertson.ch...@gmail.com writes:
(It's a 75 foot serial cable.) I suspect a software configuration
problem or maybe polarity.
If the polarity is wrong, you will just use the other edge. It will be
off
In article 87lj1q823k@cruithne.co.teklibre.org,
d...@taht.net (Dave =?utf-8?Q?T=C3=A4ht?=) writes:
Presently! It sounds like a lightly modified ntp server - or set thereof
- could actually attempt to keep track of this information.
I don't think ntpd needs any modifications.
Do ntp
It would be good if someone (or someones) has actually been collecting
rawstats for a long period, to serve as a baseline. Bufferbloat is a
relatively new phenomenon.
I'll bet it's been there for a long time. (meaning at least several
years)
I see delays up to 3 seconds, but only when I'm
In article iithjg$83s$1...@news.eternal-september.org,
David Woolley david@ex.djwhome.demon.invalid writes:
Dave T=E4ht wrote:
A well managed router would prioritised NTP traffic and isolate it from=20
the buffering, which should only really affect bulk TCP traffic.
How many routers to that?
In article 87aai6d0t6@cruithne.co.teklibre.org,
d...@taht.net (Dave =?utf-8?Q?T=C3=A4ht?=) writes:
I've been racking my brain trying to come up with a good way of
semi-passively detecting bufferbloat at the datacenter.
What would wild swings in latency on the order of seconds from a ntp
In article AANLkTi=ju-fv8e-q4rh3p7rpdf3cqncn7dpec9zrc...@mail.gmail.com,
Chris Albertson albertson.ch...@gmail.com writes:
What I'm looking for here is advice on what to check.
Is there anything interesting in the ntp log file?
(defaults to syslog which is usually /var/log/messages)
Is there
In article g7do08-bma@gateway.py.meinberg.de,
Heiko Gerstung heiko.removethistext.gerst...@meinberg.de writes:
Mmmh, the polling cycle I use is 8s (patched ntpd), and if you look
at this sample sequence ...:
Does the problem happen without that patch?
--
These are my opinions, not
In article AANLkTi=E0_9LzCDg9esXx7yZp_NJGmSU+cuS=FY9=8...@mail.gmail.com,
Chris Albertson albertson.ch...@gmail.com writes:
Could this be automated? Maybe, to some degree. The reference clock
driver would need to have a survey mode setting where it would run
for many hours and compare it's own
In article 20110112162440.ab9f81c...@ptavv.es.net,
Kevin Oberman ober...@es.net writes:
GPS satellites broadcast time in TAI, not UTC. Currently the offset
between TAI and UTC is 15 seconds.
Actually, they broadcast GPS time which is offset from TAI by
the number of leap seconds that had
In article aanlktincze9exucs_6ioz3geoexmzt3etoj7bpl6b...@mail.gmail.com,
Chris Albertson albertson.ch...@gmail.com writes:
On Wed, Jan 12, 2011 at 11:25 AM, unruh un...@wormhole.physics.ubc.ca wrote:
... There is nothing in CDMA that would require very
accurate absolute time I presume. Thus
In article 201101011238.p01ccalc009...@heartache.daihls.com,
Bruce Dale bd...@stny.rr.com writes:
...
Do you have contacts at gpsd with which you work out problems? If
not, I would be glad to provide the email addresses of the people who
were helping me. I can provide info about the problem,
In article ig0ajc$sp...@speranza.aioe.org,
Edward T. Mischanko etm1...@hotmail.com writes:
What is the prper way to determine the current version of ntpd that you have
installed or are running?
One way to find out what you are (or were) running is to scan
/var/log/messages or wherever your
In article 201012291506.obtf6xa5021...@heartache.daihls.com,
Bruce Dale bd...@stny.rr.com writes:
...
I have a Trimble Placer 450 GPS receiver generating a PPS signal and
NMEA sentences to gpsd (2.95), which passes that information to ntpd
(4.2.6p2) over the shared memory interface (reference
In article 67578d3d-adff-469a-a57b-a9ff54460...@39g2000yqa.googlegroups.com,
bombjack bombjac...@gmail.com writes:
I have STFI like crazy, but can't find an explanation for the error
code signal_no_reset: signal 18 had flags 2 Could someone
explain what this mean? Or even better, give me a
In article idpmi8$ll...@speranza.aioe.org,
Edward T. Mischanko etm1...@hotmail.com writes:
ntpd not working on a Soekris NET4501 with a nanoBSD install. Any ideas
where to start? ntpdate is working OK.
signal 11 is segmentation fault (illegal address) so something
is really screwed up.
Lots
In article 0a89d263-0355-4dee-8c9c-b4912076d...@w38g2000pri.googlegroups.com,
SteveW qsw...@email.mot.com writes:
I wanted to confirm that my understanding of the step threshold and
how it applies to ntpd used with -g -q options (similar to ntpdate) is
correct.
With the default step threshold of
In article ibm99p$ls...@speranza.aioe.org,
Edward T. Mischanko etm1...@hotmail.com writes:
I am running a Garmin 18x LVC with PPS enabled; it is very stable and I
beleave it to be accurate. My nearest back-up server is consistantly
around -8.625ms away. This is so much that other clients on
In article ibdgsl$40...@news.eternal-september.org,
David Woolley da...@ex.djwhome.demon.invalid writes:
joan lee wrote:
Wireshark runs on PC1 shows NTP client messages from 2002::c0a9:0102
+ are received properly, but instead of replying with NTP server messages,
+ PC1 is sending ICMPV6
I've found that bad things happen at much above 50ppm.
I have lots of systems that work fine at well over 50 ppm.
With a good PPS, the drift will track temperature and you
can use the system as a thermometer.
--
These are my opinions, not necessarily my employer's. I hate spam.
The most I've seen a single netperf *single-byte* burst-mode test do
is on the order of 350K transactions per second, and that is when
netperf is bound to a core other than the one taking interrupts from
the NIC to get some additional parallelism. In a netperf TCP_RR test,
netperf does virutally
[Linux TSC calibration troubles.]
YOu do not say which kernel you are using. I believe that the problem
with tsc has been fixed in later kernel versions.
Does anybody know which version it was fixed in?
--
These are my opinions, not necessarily my employer's. I hate spam.
In article qgofk7-dsb2@ntp.tmsw.no,
Terje Mathisen terje.mathisen at tmsw.no writes:
John Kennedy wrote:
We have an NTP server that we want to decommission. Before we do this we
need to know which servers are using this server to their time. Is there a
way to log which servers are syncing
I created a symlink called gps0 to my serial port ttyS0, because it
told me that in the logs when I tried to start up ntpd without it.
Can somebody who uses the NMEA driver in linux tell me if there is
something else that I should have compiled in? gpsd works fine, but
every time I switch to the
RFC 5905
Title: Network Time Protocol Version 4:
Protocol and Algorithms Specification
Pages: 110
Obsoletes: RFC1305, RFC4330
URL:http://www.rfc-editor.org/rfc/rfc5905.txt
RFC 5906
Title: Network Time Protocol
In article aanlktil2jbpj9p5eqfykgnjev8_ejr6ic_0cuodgf...@mail.gmail.com,
Marcelo Pimenta marcelopiment...@gmail.com writes:
I thought that SNTP was used in a kind of Intranet with no routers and no
internet, so the low latency there is no need of so much calculations to
adjust the clock.
I
In article 40aa2d27-9826-4948-a405-e5b311358...@z8g2000yqz.googlegroups.com,
apobrien apobriens...@gmail.com writes:
Hello list,
I have a set of proprietary hardware timing cards (Symmetricom
bc635PCIe) which synchronize their clocks using a dedicated
interconnect. As you might imagine the
In article 4c0bccfe.30...@ntp.org,
Danny Mayer ma...@ntp.org writes:
On 6/6/2010 3:24 AM, Hal Murray wrote:
https://bugs.ntp.org/show_bug.cgi?id=1568
Dave Hart points out that ntp-dev has a server option to the restrict
command.
Description here:
http://www.eecis.udel.edu/~mills/ntp
https://bugs.ntp.org/show_bug.cgi?id=1568
Dave Hart points out that ntp-dev has a server option to the restrict
command.
Description here:
http://www.eecis.udel.edu/~mills/ntp/html/accopt.html
Would somebody who uses restrict please check to see if this
does what you want.
--
These are my
In article cca1921f-cdee-43f8-bc28-31a2a0982...@a27g2000prj.googlegroups.com,
s a n ihsa...@gmail.com writes:
Thanks guys.. for the monlist and the tcpdump script info. Was exactly
what I was looking for.
Dave Hart recently cleaned this area up so the replacement for monlist
in ntp-dev now
In article
c430da47d51d0c4b940f6928bae21f4626a3f16...@sbkmxsmb06.win.dowjones.net
,
Russell, David david.russ...@dowjones.com writes:
The device is a piece of networking equipment and so I doubt that the crystal
is temperature controlled but since it is in a data center the temperature
and
In article 4beb53a2.4050...@signaturealpha.com,
Marc Leclerc marc-lecl...@signaturealpha.com writes:
Hi,
Seems the generic parser does't work with NTP with resolution SMT. Has
anyone modified some source to make it work?. NTP reports answer as bad
Data, but trimble studio hooked directly to
In article 4be025aa.4050...@signaturealpha.com,
Marc Leclerc marc-lecl...@signaturealpha.com writes:
I am trying to have NTP use the trimble resolution SMT gps module, I
have tried other trimble clock driver without success so I assume that
one specific to the module has to be used.
GPGGA has one added benefit: If you turn on clockstats you get a log of
the current position every second, this is perfect input for a
statistical averaging of the current antenna position. :-)
It doesn't have the date.
GPRMC is the only one I know of with both time and date.
--
These are
The serial chip does not do that. It will send the interrupt at the
time it has assembled a full character.
Some of the serial chips have large FIFOs and wait until the FIFO
has several characters and/or there is no activity for a while.
The idea is to save CPU cycles by batching interrupts.
How precise can a 4800 baud serial port be in determining the start of a
start bit? About 1/4800s i.e. about 200 microseconds? Don't the chips
sample at 8 or 16 times baud rate, so couldn't the start bit be determined
to ~25-30 microseconds? And if the baud rate was lot higher (the unit
I think that depends on how you set up the chip. I think you can set it
up so it will interrupt on each byte. This is not terribly efficient for
a serial port driver, but if it is timing you want, then that is
probably what you want.
On linux, I use:
setserial /dev/ttyS0 low_latency
In article 0f5de21d-2a20-40fa-ab68-a03cba5ae...@u9g2000yqb.googlegroups.com,
Evandro Menezes evan...@mailinator.com writes:
On Mar 23, 11:38=A0am, Chuck Swiger cswi...@mac.com wrote:
If I really had to solve the latter problem, I would likely connect the m=
achines to a valid NTP timesource
Modern Linux kernels don't support PPS in the sense of RFC-whateveritis.
There is support for an ioctl that says wake me up when a modem signal
changes.
gpsd uses that to provide PPS support. I don't have any data.
I believe but am not sure, that that uses an interrupt.
I think so. But
In article 4b8580e5$0$1616$742ec...@news.sonic.net,
Kelsey Cummings k...@sonic.net writes:
I'm not sure why it lost sync but I went ahead and upgraded to 4.2.7p5
from the ntp-dev port.
I'm still seeing high offset and variable jitter.
In article
1245298544.863191263816061789.javamail.r...@spooler9-g27.priv.proxad.net,
j...@free.fr writes:
Hello everybody,
for a ship project, we've got a LAN with two NTP servers
synchronised by a masterclock, itself synchronized by GPS.
The idea was to have redundancy between the 2 servers,
The fundamental problem with two servers is this: which one do you
believe when the two differ? You know that at least one of the two must
be wrong but it's impossible to determine WHICH one!
You get more than time from a packet exchange. You also get
a good idea of the accuracy. Two clocks
In article slrnhk7469.kji.un...@wormhole.physics.ubc.ca,
unruh un...@wormhole.physics.ubc.ca writes:
As I said, it is possible that all outgoing ntp requests go via a 1Gb
ethernet, and all return packets go via a 300baud modem. In that case
the estimate of 1/2 the round trip would be a good
In article slrnhjkta6.4e4.un...@wormhole.physics.ubc.ca,
unruh un...@wormhole.physics.ubc.ca writes:
ntpd has suddenly broken out into oscillations. it is fed by a Garmin
18 LVC PPS via shm. The oscillation has a period of just under an hour (
about 50 min) and an amplitude of about 10usec. in
Over the years I've come to the conclusion that it's easier to rewrite
from scratch than to reverse engineer someone else's code. Especially
so when no effort is made to document what the code is doing, the
algorithms used, what the variables represent, etc. Far too many people
code in just
Does the software include any documentation explaining what this output
means? It certainly does not seem to be in any way useful unless there
is some explanation of the output.
If there is none, I'd drop it in the garbage and use something else!
Or look at the source code.
--
These are my
but have hit some snags where certain commands are not supported in
busybox (service start/stop/reset, chkconfig).
service is just a script/program to run one of the start/stop
scritps. It may be a redhat/fedora/linux thing. google will
find the man page.
chkconfig is a utility to setup the
I have several AIX Unix 5.2 serves that point to a Cisco router as the
NTP time source.
Is there any way I could monitor the time source and against the
servers to ensure that they are in sync?
Or how are others performing time source/server monitoring?
I'm assuming you want to do the
I'm preparing to build a few ntp servers for a somewhat large population of
NTP-misbehaving boxes (they top out at a 120 sec interval).
So, to size this right - what kind of request load can I safely throw
at ntpd on a current Xeon server?
Is 200 requests per second a problem?
What do you
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