Orange is having problem delivering the internet between biggest cities (I’m traveling via train). There are white spots on the way… They do not see the problem, so I thought – lets make a chart ping-latency vs distance (location on map) Do you know any tool that could provide this statistics? I have a Gobi … Read more
A bug in gpsd upon which some NTP servers rely, has been known for a couple of months, but it hasn’t really become general knowledge until recently, just before the October 24, 2021 rollover that may set some NTP servers’ clocks back to 2002. A patch for GPSD fixes the bug. Since my company doesn’t … Read more
Is there a way to know or change the polling times of VMs running under a Hyper-V 2012 R2 server? We have set all the hosts and physical domain controllers to keep time with our new GPS time server on location. WE have read to keep the VMs set to keep time from the host. … Read more
I have NTP setup to run with GPSd and all is well. The issue arises after about a week of my raspberry pi being disconnected, NTP will trust the old date on the system clock. Since the GPS takes a couple seconds to get power and acquire a lock it seems like NTP will trust … Read more
I noticed two approaches to get an accurate time from GPS (with PPS). Using ntpd either with NMEA reference clock or Shared Memory Driver My problem: I want to have a very accurate time and access to GPS position data. Therefore using Shared Memory via gpsd is possibly to slow. In my ntp configuration I … Read more
I’m trying to configure ntpd to source it’s time from a gps receiver (BU-353S4) but I’m getting some errors. I’m using ntpd 4.2.8.p6-3 and gpsd 3.16-2 on Arch Linux Arm. I’ve been following the tutorial on the arch wiki but it doesn’t have any troubleshooting information. The gpsd log contains the entry gpsd:ERROR: response: {“class”:”ERROR”,”message”:”No … Read more
I’ve try to get high precision time from gps receiver GlobalSat BU-353s4 (/dev/ttyUSB0) through gpsd in Raspberry PI with ArchLinux. /etc/chrony.conf contains: refclock SHM 0 delay 0.5 refid NEMA refclock SHM 1 offset 0.0 delay 0.1 refid PPS refclock SOCK /var/run/chrony.ttyUSB0.sock delay 0.0 refid SOCK I’ve get time through NEMA (SHM 0 source) (but with … Read more
I have a Linux NTP server with a ublox M8Q GPS module connected via GPIO (UART @ 9600bps and PPS). What I observe is that the local GPS source — SHM(0) — gets marked as falseticker and I’d like to understand why. clock@clock:~ $ ntpq -p remote refid st t when poll reach delay offset … Read more
My server runs Ubuntu 14.04.1. I created udev rules in /etc/udev/rules.d/09-pps.rules to get GPS with PPS support work. KERNEL==”ttyS0″, SYMLINK+=”gps0″, MODE=”0666″ KERNEL==”ttyS0″, RUN+=”/bin/setserial -q /dev/%k low_latency” KERNEL==”ttyS0″, RUN+=”/usr/sbin/ldattach pps /dev/%k” /dev/pps0 will appear at startup. All right. If I check _low_latency_ flag it looks like $ sudo setserial -a /dev/ttyS0 /dev/ttyS0, Line 0, UART: 16550A, … Read more
I am attempting to add a GPS-based clock source to my network, using a GPS which emits a 1-PPS clock pulse. This is connected to a GPIO pin. After allowing ntpd to run for 30 minutes or so, the PPS clock is still not used, and marked as bad, but I cannot figure out why. … Read more
