Re: [ntp:questions] Slow convergence of NTP with GPS/PPS

2008-10-02 Thread Hal Murray
The driftfile also sometimes seems to do more harm than good - especially after a reboot. How stable is your temperature? Are you rebooting a happy system? (If so why?) Or are you powering up a system that has been off for the night? If your drift file is off, I would expect things like this:

Re: [ntp:questions] Odd (mis)behavior when reference clock fails

2008-09-26 Thread Hal Murray
Does it really make sense to get microsecond resolution on the glitches. I doubt if whatever the UPS is using for an A/D is good for microseconds. I've thought of using a wall-wart and some dividers to feed an audio input channel. That would probably be good for 10s of microseconds. I'm saving

Re: [ntp:questions] Finding out where ntpd gets its ntp.conf file

2008-09-13 Thread Hal Murray
I did get a look at the ntpd script today. Turns out the answer on where it gets the ntp.conf file is right there, near the top, in the line ntpconf=/etc/ntp.conf, even though the ntp man page points us deeper in the /etc hierarchy. The sysadmin I was working with was real annoyed, as the

Re: [ntp:questions] Finding out where ntpd gets its ntp.conf file

2008-09-12 Thread Hal Murray
No I suspect you ran /usr/sbin/ntpd, not /etc/init.d/ntpd /etc/init.d/ntpd start should do EXACTLY the same thing as when the system runs it on bootup. If I recall, the line that worked was /etc/init.d/ntpd -c filename of our ntp.conf file. I don't recall that sbin was involved. Running

Re: [ntp:questions] GPS clock for Linux

2008-09-12 Thread Hal Murray
In article [EMAIL PROTECTED], Uwe Klein [EMAIL PROTECTED] writes: Hal Murray wrote: There are a lot of low cost USB GPS gizmos that use the SiRF Star III. They suck for timekeeping. Is there a reason known for this? I assume it's a software bug/feature. The problem is drift/wander

Re: [ntp:questions] GPS clock for Linux

2008-09-11 Thread Hal Murray
I am interested in getting a GPS clock to synchronize our internal test network. I am curious to hear about relativley cheap and Linux friendly GPS clock. (Less than $100 would be great) The Garmin GPS 18 LVC is popular. Some assembly required. (aka soldering) No big deal if somebody has a

Re: [ntp:questions] Finding out where ntpd gets its ntp.conf file

2008-09-09 Thread Hal Murray
[EMAIL PROTECTED] ~]$ strings /usr/sbin/ntpd|grep ntp.conf /etc/ntp.conf In the RHEL case, this would find exactly the wrong copy of ntp.conf, being the one we were changing to no avail, not the one that NTP was in fact using. It's even worse than that. You aren't even sure that's the

Re: [ntp:questions] Finding out where ntpd gets its ntp.conf file

2008-09-09 Thread Hal Murray
Yes, and that's where strace led me, where I found a script called ntpd. How the service script interacts with this ntpd script isn't clear. Environment variables seem to be implicated, but a listing of environment variables is not helpful. Next week I'll digest it all. I think there are

Re: [ntp:questions] Finding out where ntpd gets its ntp.conf file

2008-09-09 Thread Hal Murray
[man pages] I'm happy to have more feedback on these issues. My 2 cents... I like man pages. apropos is where I start when I'm looking for things. I hate buggy documentation. That includes out of date man pages. I'd be happy with dummy man pages that told me to look in the HTML pages and

Re: [ntp:questions] The libntp resumee...

2008-09-09 Thread Hal Murray
The rules about how often to query a daemon are not all that complicated. The fact that there ARE rules is due to some history; google for Netgear Wisconsin for the sordid details. For a second opinion google for DLink PHK. There is a good summary at: NTP server misuse and abuse

Re: [ntp:questions] nmea stopped working all of a sudden

2008-08-22 Thread Hal Murray
That worked out of the box and all of a sudden just stopped. Since I changed a lot of things in order to make the box work fully-automatic, I can't say for sure if I broke something or what happened.. Still I am very puzzled... Maybe I overlooked something? Here's some information: Here's my

Re: [ntp:questions] very confusing results though using pps and nmea

2008-08-13 Thread Hal Murray
Note that serial port nmea is liable to be out by up to 1/2 sec and to have a lot ( 10s of msec) jitter on it, since the end of the string received by a slow serial port ( eg at 4800Bd, it takes an nmea sentence of about 60 characters 1/8 of a second to be delivered and will have a jitter of few

Re: [ntp:questions] NTPD concurrent clients limit

2008-08-13 Thread Hal Murray
His question can be rephrased, what does ntpd do after it has sent the Kiss of Death? does it drop all subsequent packets? -- That sounds like a huge cost on the ntp server-- ie imagine a popular server with 10,000 machines it has sent the KoD to. It then has to scan that whole list for each

Re: [ntp:questions] Time going backwards

2008-08-13 Thread Hal Murray
I wouldn't get terribly upset about it. Ntpd does not step the time unless it is grossly wrong. Ntpd has been known to step *FORWARD* on certain Windows and MAYBE Linux systems when heavy disk activity resulted in missed clock ticks. I can't think of anything likely to go wrong that would

Re: [ntp:questions] drift modeling question

2008-07-15 Thread Hal Murray
Historically interrupts from the 32kHz clock have not been used, except, possibly, in powered down states to initiate a restart from suspend or hibernate. It is possible that has changed very recently, but they certainly weren't used historically. Well, at least one of us is confused. Or maybe

Re: [ntp:questions] drift modeling question

2008-07-13 Thread Hal Murray
Correct, in that the linear correction will vary with temperature (and could be matched closely by a quadratic) I don't think you can measure the temperature and/or drift accurately enough to make quadratic corrections interesting. I am thinking of a least-squares fit to the drift data,

Re: [ntp:questions] drift modeling question

2008-07-11 Thread Hal Murray
In article [EMAIL PROTECTED], shy author [EMAIL PROTECTED] writes: Has anyone thought about removing both the linear terms and quadratic terms in the drift, by utilizing the temperature sensor readings available on many of the latest motherboards? Linear works pretty well. I think it would be

Re: [ntp:questions] Multicast and dynamic interfaces

2008-07-10 Thread Hal Murray
Should ntpd be able to listen for multicasts on interfaces that get added/configured after ntpd starts? Is this a common enough situation to justify the coding effort required? It seems to me to be a hell of a lot easier just to configure all your interfaces, or at least all you want to use,

Re: [ntp:questions] Ruh, roh. Leap Second?

2008-07-02 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] (Peter Laws) writes: 1 Time(s): Clock: inserting leap second 23:59:60 UTC RHEL 5.2 system running ntpq [EMAIL PROTECTED] Thu Jan 17 18:14:14 UTC 2008 (1) which is the default for that distribution. Grepping around in the logs it appears that most

Re: [ntp:questions] Frequency Error on Sun4v

2008-06-20 Thread Hal Murray
[drift 500 ppm] It's almost certainly a hardware problem. Ntpd is telling you that the clock is gaining, or losing, more than about 43 seconds (500 parts per million) per day. 500 PPM is the maximum that ntpd can handle. It could easily be a software screwup. Unless you know it works on

Re: [ntp:questions] Drift from serial activity, VIA system, LInux

2008-06-08 Thread Hal Murray
In article [EMAIL PROTECTED], David Woolley [EMAIL PROTECTED] writes: Hal Murray wrote: The quirk is that the drift changes when I run the monitoring program. It changes more if I poll faster. It changed by 20 ppm when I was polling with a 10 ms delay and it's more than 80 ppm and still

[ntp:questions] Drift from serial activity, VIA system, LInux

2008-06-07 Thread Hal Murray
I'm setting up a small system to monitor things like line voltage and temperature. It uses a serial connection to a UPS box to get the line voltage. The quirk is that the drift changes when I run the monitoring program. It changes more if I poll faster. It changed by 20 ppm when I was polling

Re: [ntp:questions] Getting PPS on a modern rack-mounted server?

2008-05-29 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] (John Ioannidis) writes: This may sound like an embarrassment of riches, but here is my problem: I have some rack-mounted servers (IBM System x3650 to be precise) that I need to synchronize with a PPS signal. The problem is, of course, that the

Re: [ntp:questions] NTP phase lock loop inputs and outputs?

2008-05-19 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] [EMAIL PROTECTED] writes: I'm doing NTP exchanges to determine my clock offset. I use this to adjust my clock frequency, but there's a lot of lag so I overshoot by too much and it oscillates around the reference frequency. This is an audio clock so

Re: [ntp:questions] Sudden frequency offset jump

2008-05-07 Thread Hal Murray
On April 30, the time offset started climbing and reached 14 ms in approximately 90 minutes. ntpd started bumping the frequency offset, down to -9.4 ppm. Is this the Linux TSC bug? Are you running a recent Linux kernel? Did you reboot the system at that time? -- These are my opinions, not

Re: [ntp:questions] Sudden frequency offset jump

2008-05-07 Thread Hal Murray
I didn't check the amount of the jump. I would not expect a jump of more than a few ppm (due to the crystal itself), and not more than about once a year. It was 3 or 4 ppm. That's big enough that I think it very unlikely, but not impossible. Even if it happened only once per year, somebody

Re: [ntp:questions] Sudden frequency offset jump

2008-05-02 Thread Hal Murray
In article [EMAIL PROTECTED], Noob [EMAIL PROTECTED] writes: Hello, One of my systems had been running for ~6 weeks. During this time, the frequency offset computed by ntpd remained stable between -6.6 ppm and -6.2 ppm. On April 30, the time offset started climbing and reached 14 ms in

Re: [ntp:questions] ntpd and High resolution timer

2008-04-30 Thread Hal Murray
Does the HPET support enable microsecond resolution for hardware clock reads in Linux (the HPET hardware is supposedly capable of this)? I don't know. A quick test with my kernel seemed to ignore that chunk of the command line. I may have it turned off in the config file. -- These are my

Re: [ntp:questions] A question

2008-04-30 Thread Hal Murray
I would like to connect to any server to receive a string where it is written the istant time (possibly hh.mm.ss.xxx ). I found several sites where I may read hh.mm.ss then downloading the page and reading it I could get the string hh.mm.ss but I don't know of any servers that do that. In the

Re: [ntp:questions] ntpd and High resolution timer

2008-04-29 Thread Hal Murray
I am using NTPd and I have guessed that it uses the High Resolution Timer, brought to the linux kernel since the 2.6.16 release. Does anyone know if it said somewhere in the documentation or any other official source, a trusty one. ntpd just calls the kernel. Recent Linux kernels have several

Re: [ntp:questions] ntpd and High resolution timer

2008-04-29 Thread Hal Murray
I haven't seen that problem since I added clocksource=acpi_pm on the boot time parameters. What version of the kernel do you have? 2.6.17 does not have clocksource parameter or an acpi_pm option. Is there anywhere where these different clock parameters are defined? I'm using 2.6.23.

Re: [ntp:questions] frequency adjusting only

2008-04-27 Thread Hal Murray
Sorry it's actually difficult for me to precise this topic for confidentiality reason of course and also because I'm an intern and thus there for a short period. Hence I don't know exactly why myself. This is just one of the requirement of my project. Keeping a handful of machines synchronized to

Re: [ntp:questions] frequency adjusting only

2008-04-25 Thread Hal Murray
I actually don't really understand why a GPS would improve my synchronisation. If your master server has GPS, its time will be more stable. That means your clients can sync to a stable clock rather than trying to track a clock that is wobbling around. (Things are simpler and work better when

Re: [ntp:questions] Problem monitoring NTP synchronization status

2008-04-22 Thread Hal Murray
$!/bin/sh if ! ntpq|grep '* name.of.router'/dev/null; then mail -s NTP sync has been lost [EMAIL PROTECTED] fi And put the shell script into crontab to run every minute. (your milage may vary) That could lead to a lot of clutter in your mailbox. -- These are my opinions, not necessarily my

Re: [ntp:questions] Time slew doesn't seem to work

2008-04-12 Thread Hal Murray
Do you know any code that cares if that is wrong by 10% (which would be 10PPM) Ie, is 10% error insane? Is 1% (1PPM)? Ie, .05% seems a bit extreme for that. I used to do a lot of performance measurements. For the stuff I was doing, 10% is easy to spot. 1% is borderline. -- These are

Re: [ntp:questions] Problem with time synchronisaton

2008-04-12 Thread Hal Murray
The problem here is that the distribution does not contain a decent assortment of example configuration files for common configurations. So the OS distributors/aggregators/vendors each cobble together their own one size fits all configuration file. But does a local refclock make sense in a

Re: [ntp:questions] Time slew doesn't seem to work

2008-04-09 Thread Hal Murray
Well, no. 1 or 2 sec is 10-20PPM which is on the good side. 43 sec per day is like 500PPM which is definitely on the high side. 5-10sec per day is more typical. Note that chrony(on linux) will fix 43s/day. (It will use the fast slew-- ie changing the tick size-- as well as the slow slew.) ntp as

Re: [ntp:questions] Setting up a NTP Time Server

2008-04-08 Thread Hal Murray
Can someone point me to a good document that shows how to setup a Time Server? I have an isolated network that cannot get to the Internet to sync time. I have Solaris 8,9,10 and Red Hat Linux Advanced Server 4 servers as potential time server candidates. I don't know of any document that covers

Re: [ntp:questions] Setting up a NTP Time Server

2008-04-08 Thread Hal Murray
I assume that you mean to use both the refclock_atom and the refclock_nmea drivers. (127.127.22.0 and 127.127.20.0) The NMEA driver automagically uses the PPS stuff, whether you want it to or not. It would be nice to have a flag to disable that feature so you could collect data on the NMEA text

Re: [ntp:questions] Time reset

2008-04-04 Thread Hal Murray
My current problem is that drift settles at 82ppm (what I called 90 in previous email) in one run and then 32ppm in another run (with a reboot between). This is similar to the problem I had with stepping disabled where drift would go from +500ppm in one run and then swing all the way to -500ppm

Re: [ntp:questions] Linux 11-minute mode (RTC update)

2008-04-04 Thread Hal Murray
Fine! Don't touch anything, happy man, or it might well tomber en marche. Real men don't want the eleven-minutes mode. It is not only extremely inaccurate by itself, but it also steps on the toes of those tools that are able to manage the RTC properly. Would somebody please collect this info on

Re: [ntp:questions] Time reset

2008-04-04 Thread Hal Murray
As I've stated before, I don't believe the oscillator is really this unstable, but I could be wrong. After all, my CPU measurements varied much more than yours, especially from one run to the next. However, I'm still open to the possibility that linux's approach to speed measurement is less

Re: [ntp:questions] Time reset

2008-04-03 Thread Hal Murray
The ntp log file shows when NTP steps the time. But then the potential harm is already done. Especially if the time moves backward, our server might have serious trouble. Is there a log event which indicates that the time is going to be reset in order to enable us to take appropriate action

Re: [ntp:questions] high precision tracking: trying to understand sudden jumps

2008-04-01 Thread Hal Murray
The basic idea is to do the time stamping in hardware deep in the network adaper. That avoids lots and lots of jitter. Yes, PTP can yield an accuracy better than 100 ns if both the NICs at the clients and the server support hardware timestamping of sent/received PTP packets. I am still

Re: [ntp:questions] high precision tracking: trying to understand sudden jumps

2008-04-01 Thread Hal Murray
Yes, PTP can yield an accuracy better than 100 ns if both the NICs at the clients and the server support hardware timestamping of sent/received PTP packets. On the other hand, also *every* network node between the PTP endpoints has to be PTP-aware and compensate the packet delay it introduces,

Re: [ntp:questions] ntp discipline of local time?

2008-03-26 Thread Hal Murray
I am willing to believe, barring contrary evidence, that your faithfully implimented the protocol. (and that the Linux people faithfully implimented the protocol in the kernel discipline routines). Don't be so quick to believe that things work as expected. I seem to remember a report of some

Re: [ntp:questions] Disk read hack

2008-03-23 Thread Hal Murray
In article [EMAIL PROTECTED], Harlan Stenn [EMAIL PROTECTED] writes: In article [EMAIL PROTECTED], [EMAIL PROTECTED] (Hal Murray) writes: Hal I didn't find a reasonable place to insert it in the wiki so I parked Hal it here for now. Hal http://www.megapathdsl.net/~hmurray/hacks/read.c How

[ntp:questions] Disk read hack

2008-03-20 Thread Hal Murray
I didn't find a reasonable place to insert it in the wiki so I parked it here for now. This is a hack that just reads a disk as fast as it can. It was very good at tickling the lost-interrupt problem on an old RH system which was not using DMA on the disks.

Re: [ntp:questions] Antenna for TymServe?

2008-03-20 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] (Peter Laws) writes: I've resuscitated a left-for-dead TS 2100 and now am in need of a Trimble Bullet III, or equivalent, active GPS antenna. It's a current item for Symmetricom and they want more dinero than I want to put into this 12 year old

Re: [ntp:questions] SNTP server + ntpd 4.2.4 client

2008-03-19 Thread Hal Murray
I've never used the GPS18LVC (I have a Motorola M12+T) but if you know your exact location you only need one satellite to get the time. There are four equations in four unknowns (lattitude, longitude, elevation, and time). Not knowing any of these variables, you need four satellites. Once

Re: [ntp:questions] SNTP server + ntpd 4.2.4 client

2008-03-19 Thread Hal Murray
Does the GPS18LVC provide an oscillator to serve time even when there are not enough satellites in sight? No. -- These are my opinions, not necessarily my employer's. I hate spam. ___ questions mailing list questions@lists.ntp.org

Re: [ntp:questions] Time reset

2008-03-13 Thread Hal Murray
So its the DISK I/O thats causing loss of ticks ? My first Red Hat system defaulted to no-DMA for IDE disks. (Yes, that was a long time ago.) With that setup, it was simple to generate lots of lost timer interrupts: just keep the disk busy doing reads. (Seeks don't count. Read consecutive

Re: [ntp:questions] Too much offset from GPS?

2008-03-07 Thread Hal Murray
I have problem with my stratum1 box. My box include: freebsd 5.2-RELEASE without PPS , ntp-4.2.0_1, Intel Pentium III, 40 G IDE, Germin GPSmap60 , connect with serial com. In GPSmap60 set as NMEA. Freebsd box can get NMEA input string. My configuration of ntp.conf like this: server

Re: [ntp:questions] Starting ISC NTP -4.2.4

2008-02-13 Thread Hal Murray
Iam trying to install ISC NTP-4.2.4 on RHEL 4. But Im not able to start the services. I firstly removed the default rpm and then compiled the latest version, configured the ntp.conf file, but Iam not able to start the service. I give the command /etc/init.d/ntpd start. # prompt comes back.

Re: [ntp:questions] ntpdate.c unsafe buffer write

2008-02-12 Thread Hal Murray
I was talking about what people could expect from software that behaved well; I think you are describing what ntpd actually does here. My point was that ntpd's ability to tolerate really rotten links is irrelevant for most users, who are only about 20ms away from their ISP's time server, and

Re: [ntp:questions] ntpdate.c unsafe buffer write

2008-02-11 Thread Hal Murray
So, no, I am comparing apples to apples ( the offsets as determined from the ntp packet exchange mechanism which both use and both report). Another approach is to setup a 3rd machine to watch both. -- These are my opinions, not necessarily my employer's. I hate spam.

Re: [ntp:questions] GCC-4.2.3 Compiler Error in NTP-4.2.2p4

2008-02-09 Thread Hal Murray
First, somebody gets to decide if this is really a bug in the NTP code or if it is a bug in GCC. It could also be a glitch in the included header files. -- These are my opinions, not necessarily my employer's. I hate spam. ___ questions mailing

Re: [ntp:questions] NTP no internet connection

2008-02-09 Thread Hal Murray
What does all over the map mean. they will be withing a few tens of microseconds of that server. I'd expect a few to tens of ms rather than microseconds. If you manually set the time on the server, I'd expect it to take a while for the clients to catch up. This question comes up often enough

Re: [ntp:questions] very slow convergence of ntp to correct time.

2008-02-03 Thread Hal Murray
However, you give me an idea. Why not shut down the burst when the clock filter delivers the first sample? Gotta think about that. That would make sense if the goal is to get an answer on a lossy system. I think the background in this discussion was not loss, but delays in setting up

Re: [ntp:questions] First attempt GPSD/PPS -NTP time server

2008-01-27 Thread Hal Murray
I am afraid I simply do not believe this. NMEA is lucky to get a ms not a usec. The offset on the NMEA should be a lot bigger than .001 The NMEA driver includes built-in PPS support. -- These are my opinions, not necessarily my employer's. I hate spam.

Re: [ntp:questions] NTP vs chrony comparison (Was: oscillations in ntp clock synchronization)

2008-01-22 Thread Hal Murray
On recent Linux kernels, I think the drift file is always bad after reboot. HZ=100, no dynamic ticks aka tickless system (CONFIG_NO_HZ not set). I think I even tried with a kernel command line option lpj= but it didn't help. If the system is rebooted, ntpd stabilizes to a new different drift

Re: [ntp:questions] oscillations in ntp clock synchronization

2008-01-15 Thread Hal Murray
In article [EMAIL PROTECTED], Bill Unruh [EMAIL PROTECTED] writes: I have been keeping track of the clocks on my various systems. One is synced using ntp from a GPS 18LVM pps source. The others are synced from What is a GPS 18LVM? I've seen it mentioned several times recently. From the

Re: [ntp:questions] using both a PPS source and a HBG (dcf-77-like) timesource?

2008-01-14 Thread Hal Murray
Currently I'm syncing against NMEA/PPS and seeing quiet a big offset: remote refid st t when poll reach delay offset jitter == xGPS_NMEA(0) .GPS.0 l7 16 3770.000

Re: [ntp:questions] using both a PPS source and a HBG (dcf-77-like) timesource?

2008-01-14 Thread Hal Murray
To my pc I have connected a garmin 18lvc and a HBG radio clock receiver. Now what I would like to do is: - let the hbg receiver set the current time and when the HBG signal is not available (bad reception or the 59 seconds while it is receiving the broadcastmessage) use the PPS signal of the

Re: [ntp:questions] using both a PPS source and a HBG (dcf-77-like) timesource?

2008-01-14 Thread Hal Murray
Ok but the odd thing is: a friend of mine has the exact same garmin 18 lvc but not this big offset? Your PPS isn't working. That could be either hardware or software. What OS are you using? What version of ntpd? What is your friend using? How about taking your unit over to his place and

Re: [ntp:questions] using both a PPS source and a HBG (dcf-77-like) timesource?

2008-01-13 Thread Hal Murray
The radio receiver will be late by of the order of millisec, while the gps will be on time to microseconds. Of course you may not care, but someone who has two onboard time sources would care, I would think. The radio propagation delay can be fudged out. How stable is

Re: [ntp:questions] quirky adjtimex behaviour

2008-01-05 Thread Hal Murray
I am seeing strange behaviour on my _x86_64 Fedora 7 desktop workstation with regard to the system-cmos time that `adjtimex' reports. That leaves the RTC doing the jumping. But having an RTC that is runing nearly 1 ppm slower than my system clock and which jumps ahead every 10 seconds seems

Re: [ntp:questions] Distribution security

2008-01-05 Thread Hal Murray
When I wrote that I was unaware of the html page. I'm a Unix guy and I generally don't even consider looking for html docs - I am used to (and expect) man pages. Me too. Would it help to ship dummy man pages that just pointed to the html documentation? -- These are my opinions, not

Re: [ntp:questions] why is this clock not even considered?

2007-12-25 Thread Hal Murray
Why is the '.SHM.'-clock not even considered? Because of the negative offset? Negative offsets are not a problem. They happen all the time. My guess is that something your new driver is setting up makes your clock look not-very-good. It's probably one of the obscure constants that aren't well

Re: [ntp:questions] Criteria for evaluating upstream server quality

2007-12-22 Thread Hal Murray
Some stratum 2 servers I get time from are actually polling stratum 1's that have a pretty significant round-trip (more than 70ms), so is this any better than having my ntp getting its time from a stratum 3 or 4 that's closer to its own upstream sources? A long round-trip time isn't evil all

Re: [ntp:questions] Configuring FreeBSD 6.2 for use with Garmin GPS 18 LVC

2007-12-20 Thread Hal Murray
One possibility may be that the GBS18 has switched to Garmin mode instead of NMEA mode. That seems unlikely. You have to send it a sensible command. Garbage on the line is not likely to do that. On the other hand, maybe he ran some software that knows about Garmin GPS units... My GPS18

Re: [ntp:questions] Why false tickers one day, and not the next day?

2007-12-17 Thread Hal Murray
The nodes' drifts are high: # cat /etc/ntp.drift node-A: 499.206 node-B: 497.070 500 ppm is the limit. The next day, after restarting ntpd on the nodes and resetting the time on all nodes with ntpdate, everything worked as expected with the time syncing properly, no false tickers, and the

Re: [ntp:questions] Trace ntp sanity checks?

2007-12-15 Thread Hal Murray
assID‡73 status14 reach, 1 event, event_reach, srcadrmaster1, srcport3, dstadr0.0.0.0, dstport3, leap You see, it's garbage again. It's hard to keep up under this circumstances. My copy wasn't garbled. It looked like this: assID=8773 status=1014 reach, 1 event, event_reach,

Re: [ntp:questions] Linux as clients not synching with Win/Tardis Time server

2007-12-09 Thread Hal Murray
Don't. Just have the Linux servers point to external servers like the pool and then you don't have to change anything later. You are likely to get better quality time service that way. Tardis is a bit short on technical information so it's hard to tell what it does, how it does it and how

Re: [ntp:questions] SNMP support

2007-12-08 Thread Hal Murray
It would be very handy if one could monitor NTP with the same tools used for monitoring other aspects of performance, rather than having to use special programs like ntpq and parse its output. I'm thinking of this an addition to the present tools, though, not a replacement. Is there anything

Re: [ntp:questions] Trace ntp sanity checks?

2007-12-06 Thread Hal Murray
Too many packaging of ntpd configure a local clock driver in their sample configuration. Does anybody know why that got started? What urban legend do we have to stomp out before that practice will go away? -- These are my opinions, not necessarily my employer's. I hate spam.

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-04 Thread Hal Murray
1. Accord GPS Clock spits out NMEA at 9600 baudrate The NMEA specs call for 4800. Is there some way to set the Accord box to run at 4800? That seems only sensible if they are in the NMEA market. 2. It has custom NMEA format for GPS (and the driver is intended to use this )

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-04 Thread Hal Murray
I I don't know; it seems to me better for the refclock driver to specify a default set of comm parameters that will work for the standard device that refclock supports, but have a universal mechanism that would allow overriding those params from the config file and would work for any driver.

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-04 Thread Hal Murray
Over the years and with some effort several drivers now support more than one device. All TrueTime models are supported by one driver; all Spectracom models by another and all telephone modem services by a third. With few exceptions, a NMEA radio is a NMEA radio and I strongly suspect many of

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-04 Thread Hal Murray
Perhaps the best way is to add a completely new command refclock and load it up with all kinds of options, including those now done by the fudge command. The command would not need the dotted quad, which could be replaced by the driver name already in a table. The syntax could in principle be

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-03 Thread Hal Murray
The NMEA driver uses 3 mode bits. I think more are available. The docs say that flag1 is unused for the NMEA driver. It would be really nice if there was a clean way to specify the baud rate. Several of the NMEA units I'm familiar with allow you to set the baud rate they use. I expect there

Re: [ntp:questions] Reg: NTP accuracy

2007-12-03 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] (linux newbie) writes: HI, Need following clarification. Our Application needs to have two individual hardware (with DSP processor) to have same crystal clock freqency. Though individual boards are alike, due to environmental factors there might be

Re: [ntp:questions] Issues with ACCORD Reference Clock Driver

2007-12-03 Thread Hal Murray
It would be really nice if there was a clean way to specify the baud rate. This is a general issue -- there are other drivers (e.g. the HP 58503) that also assume a fixed baud rate and parity/stop bits. They cause a lot of problems when trying to use not-quite-identical hardware (as in

Re: [ntp:questions] Any samples for NTP/SNTP client code?

2007-12-01 Thread Hal Murray
In article [EMAIL PROTECTED], [EMAIL PROTECTED] writes: Does anybody know of any *practical* samples on how to implement NTP/SNTP client?. The goal is to provide accurate time for a program/client running on Windows Vista. Just curious. Why do you want to roll your own as compared to run one of

Re: [ntp:questions] drift file set to -500

2007-12-01 Thread Hal Murray
Yes. And one missing step: After stopping ntpd, ntpdate -b [server]. The single most common cause of a large negative drift value is a system whose clock has not been initialized before starting ntpd (or has been stopped during a large time adjustment). What vintage of ntpd are you using?

Re: [ntp:questions] Wireless Routers and NTP

2007-11-29 Thread Hal Murray
Routers generally do not do NTP in any way, shape, or form! They don't need to know the time! That's misleading. Routers often include anti-spam/abuse mechanisims which get logged. It helps if the time stamps on the log files are correct. It's easier to get that if the router itself uses NTP

Re: [ntp:questions] drift file set to -500

2007-11-29 Thread Hal Murray
I don't think it's a hardware product defect. Because we have two of them, and we had run the same test on both of the board, we still got the same error. Thanks, There are two kinds of hardware (or software) errors. One is a design error. The problem happens all the time on all units. The

Re: [ntp:questions] Wireless Routers and NTP

2007-11-29 Thread Hal Murray
Why do you feel that your router needs to know the time? Log files for security incidents. -- These are my opinions, not necessarily my employer's. I hate spam. ___ questions mailing list questions@lists.ntp.org

Re: [ntp:questions] Details about code structure

2007-11-21 Thread Hal Murray
Would such a document really be all that useful? It seems to me that the codebase is pretty small, and it should not be all that hard to figure out. I use grep whatever *.c or grep whatever -r . If that doesn't work in the directory I'm working in, then I cd .. and try again. After doing

Re: [ntp:questions] Details about code structure

2007-11-21 Thread Hal Murray
I had my computer count the lines of code in one of the older versions, about two years ago. 70,000 or so lines of code may be a small number to you but it seems like a lot to me. I once looked at the code for the Motorola Oncore driver to try to understand what was going on and failed. It

[ntp:questions] Looking for help testing SHM driver improvements

2007-11-11 Thread Hal Murray
The current SHM driver looks for a sample each polling interval. The documentation for gpsd suggests using minpoll and maxpoll of 4. I've fixed the SHM driver to look every second. The refclock infrastructure already had a FIFO and code to process things like this. This reduces the jitter

Re: [ntp:questions] Inexpensive OEM GPS units?

2007-11-11 Thread Hal Murray
Although from all the other replies (thanks everyone), it sounds like maybe there really just aren't tons of other cheap OEM options. Your original request wanted a PPS signal. If you don't really need that, you have a lot more options. There are many low cost GPS units with USB connections.

Re: [ntp:questions] NTP + kernel frequency

2007-11-10 Thread Hal Murray
On Linux, a simpler way can be to look at /proc/interrupts - e.g. (probably Linux-version- and possibly config-specific): $ (cat /proc/interrupts; sleep 10; cat /proc/interrupts) | \ awk '/timer/{prev=now; now=$2} END{printf %dHz\n, int((now-prev)/10)}' This yields 41Hz on my Via C7

Re: [ntp:questions] NTP and NAT

2007-11-08 Thread Hal Murray
The second thing, is that ntp through NAT would get a variable latency point (since NAT speed of most routers vary with router traffic load). I think you are talking about CPU latency rather than wire latency. (Wire latency doesn't depend upon NAT.) My NAT box is a DSL router. The CPU is

Re: [ntp:questions] NTP + kernel frequency

2007-11-08 Thread Hal Murray
I known now, in the recent kernel the internal frequency will be to 250 Mhz... With my gentoo it's not a problem for me because i make myself my kernel ... but if i take Mandriva or a another distribution how find this values ? I assume you mean the scheduling clock which would be 250 Hz rather

Re: [ntp:questions] Reference clock all messed up?

2007-11-07 Thread Hal Murray
server 192.168.1.1 # by default ignore all ntp packets restrict default ignore # allow localhost restrict 127.0.0.1 mask 255.255.255.255 # accept packets from... restrict 192.168.2.0 mask 255.255.255.0 nomodify notrap restrict 192.168.3.0 mask 255.255.255.0 nomodify notrap restrict 192.168.4.0

Re: [ntp:questions] TimeStamp

2007-10-30 Thread Hal Murray
I'm very confused on how ntp do the timestamp. I'm running ntpd on vxworks. It seems to me that the receive timestamp and the Transmit timestamp are using two different clocks, because when I use ethereal/ wireshark to look up the information of the ntp packet, the Recevie Time Stamp is: Jan 1,

Re: [ntp:questions] How to choose time servers

2007-10-26 Thread Hal Murray
In article [EMAIL PROTECTED], Patrick Nolan [EMAIL PROTECTED] writes: I'm located at a university. We have a master Stratum 1 server with a GPS clock. We also have at least four Stratum 2 servers which are synchronized with the master. These are all very close, with delay and offset values

Re: [ntp:questions] Can a clock drift be too big for ntpd?

2007-10-24 Thread Hal Murray
In article [EMAIL PROTECTED], Patrick Nolan [EMAIL PROTECTED] writes: On 2007-10-20, Steve Kostecke [EMAIL PROTECTED] wrote: The hardware clock in a PC is made of exceedingly cheap components. A common quartz wristwatch is a better clock. I have noticed this. Until WWV-controlled clocks came

Re: [ntp:questions] Can a clock drift be too big for ntpd?

2007-10-20 Thread Hal Murray
A bad clock frequency is a hardware issue! Or a software bug. There have been troubles with roundoff on the value of the tick size. -- These are my opinions, not necessarily my employer's. I hate spam. ___ questions mailing list

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