Bug 1478074
| Summary: | Fedora 26 upgrade breaks ntp pps | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | udo <udovdh> |
| Component: | ntp | Assignee: | Miroslav Lichvar <mlichvar> |
| Status: | CLOSED NOTABUG | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 26 | CC: | linville, mlichvar, udovdh |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2018-02-27 10:28:23 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
udo
2017-08-03 14:16:34 UTC
Do you set flag3 to 1 for the NMEA refclock? The Fedora kernel doesn't support PPS kernel discipline and older ntp versions silently ignored the error. # grep ^ntp /etc/services ntp 123/tcp ntp 123/udp # Network Time Protocol # grep ^services nsswitch.conf services: files # Kernel 4.9.40 has: # grep PPS .config # PPS support CONFIG_PPS=y # CONFIG_PPS_DEBUG is not set # PPS clients support CONFIG_PPS_CLIENT_KTIMER=m CONFIG_PPS_CLIENT_LDISC=y # CONFIG_PPS_CLIENT_PARPORT is not set # CONFIG_PPS_CLIENT_GPIO is not set # PPS generators support # Just like previous kernels that worked wonders. I use my own kernel. Because. And now two things break. PPS. And network clocks. I did not change anything in ntp.conf for ages: # grep -v ^# ntp.conf server 127.127.20.0 minpoll 4 fudge 127.127.20.0 flag3 1 flag2 0 flag1 1 time1 0.00000006 time2 0.160 disable monitor restrict default kod nomodify notrap nopeer noquery restrict -6 default kod nomodify notrap nopeer noquery server surfplank2 server ntp.xs4all.nl server ntp2.xs4all.nl server ntp0.nl.net server ntp2.nl.net server keetweej.vanheusden.com server ntp.nmi.nl driftfile /var/lib/ntp/drift broadcastdelay 0.008 logconfig -syncstatus -sysevents logfile /dev/log discard average 5 minimum 2 restrict 127.127.0.0 mask 255.255.0.0 nopeer # internal clocks restrict 127.0.0.1 mask 255.255.255.255 # accept local network restrict ::1 # accept local network restrict 192.168.10.0 mask 255.255.255.0 nomodify notrap nopeer # notrust statistics loopstats statsdir /var/log/ntp/ filegen peerstats file peers type day link disable filegen loopstats file loops type day enable # Even worse: When ntpd does not run in chroot things appear OK. When in chroot the symptoms as described happen. So the issue has to do with chroot. strace did not yet yield any clues. In chroot /dev/log is no longer found although /dev/log is present: # ls -l /dev/log srw-rw-rw- 1 root root 0 Aug 3 15:39 /dev/log # ls -l /chroot/ntpd/dev/log srw-rw-rw- 1 root root 0 Aug 3 15:39 /chroot/ntpd/dev/log Yet we see: Aug 3 16:34:36 epia ntpd[10618]: Cannot open logfile /dev/log: No such device or address And perhaps we can explain these: Aug 3 16:34:36 epia ntpd[10618]: refclock_params: time_pps_kcbind: Operation not supported Aug 3 16:34:36 epia ntpd[10618]: GPS_NMEA(0) set PPSAPI params fails by the GPS serial ports not being found in the chroot /dev but in the system /dev. This has worked for years but is now broken. Your kernel config is missing CONFIG_NTP_PPS. Please recompile the kernel with that option enabled (you will need to disable NO_HZ) or remove "flag3 1" from ntp.conf. As for the chroot, does it include the /etc/service file? Kernel 4.9.40 .config does not have CONFIG_NTP_PPS. Having services and nsswitch.conf in /chroot/ntp/etc does not have any impact, behaviour does not change: # ls -l /chroot/ntpd/etc/ total 684 -rw-r--r-- 2 root root 1834 Aug 3 16:18 nsswitch.conf drwxrwx---. 2 root ntp 4096 Oct 24 2004 ntp -rw-r-----. 2 root ntp 3315 Jun 8 2015 ntp.conf -rw-r--r-- 2 root root 687295 Dec 7 2016 services When not running in chroot, ntpq -pn reports all local and remote clocks. But: # /usr/sbin/ntpdc -c loopinfo localhost.localdomain: timed out, nothing received ***Request timed out Why? This worked before the upgrade. Have you tried "strace -ff ntpd -d -u ntp |& grep open" to see what files it is missing? ntpdc doesn't work in default configuration. The protocol is disabled by default as it allows very large traffic amplification. It can be enabled by adding "enable mode7" to ntp.conf. enable mode7 added, thanks. the strace reveals that, besides some libs that are not on my system anyways, only /dev/log is not found. Yet /dev/log and /chroot/ntpd/dev/log both exist. If I understand it correctly, all issues mentioned here were either resolved by updating the ntp configuration or need to be addressed outside ntp (kernel configuration, chroot setup). I'm closing the bug. |