RE: SL7 - crond starting before chronyd causing problem with mrtg {solved - I think}
Hmm It seems that I forgot that kvm by default only suspends the guests when you reboot the host. This explains the delay in resyncronising the clock, etc. I've now fixed up the /etc/sysconfig/libvirt-guests on the host to ensure a reboot of guests. I'm now awaiting the next reboot (a scheduled power outage on Tuesday) to prove the point. Sorry all for the noise; at age 68 the little grey cells aren't what they used to be. Cheers Bill -Original message- From: Bill Maidment b...@maidment.me Sent: Thursday 22nd January 2015 18:26 To: scientific-linux-users@fnal.gov Subject: RE: SL7 - crond starting before chronyd causing problem with mrtg Thanks David. However, even using After= chronyd.service the chronyd still takes too long to correct the time for the time-zone. After some investigation, it seems that the KVM system is at fault when the host is rebooted, but not when the guest is rebooted. On reboot of the host KVM adds the timezone shift to the hardware clock for the guests and then the guest adds the timezone shift again. This extra addition of the timzone shift did not happen on SL6. After running hwclock --systohc on the guest, I get the following setup. [root@giggs2 ˜]# timedatectl Local time: Thu 2015-01-22 17:55:26 AEDT Universal time: Thu 2015-01-22 06:55:26 UTC RTC time: Thu 2015-01-22 06:55:26 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ˜]# On reboot of just the guest, I get the following, the RTC looks OK: [root@giggs2 ˜]# timedatectl Local time: Thu 2015-01-22 18:05:09 AEDT Universal time: Thu 2015-01-22 07:05:09 UTC RTC time: Thu 2015-01-22 07:05:09 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ˜]# On reboot of the host, I get the following on the guest, the RTC looks wrong: [root@giggs2 ˜]# timedatectl Local time: Fri 2015-01-23 05:15:41 AEDT Universal time: Thu 2015-01-22 18:15:41 UTC RTC time: Thu 2015-01-22 18:15:42 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ˜]# Regards Bill Maidment -Original message- From:David Sommerseth sl+us...@lists.topphemmelig.net Sent: Wednesday 21st January 2015 23:33 To: Bill Maidment b...@maidment.me; SCIENTIFIC-LINUX-USERS@FNAL.GOV SCIENTIFIC-LINUX-USERS@fnal.gov Subject: Re: SL7 - crond starting before chronyd causing problem with mrtg On 21/01/15 12:18, Bill Maidment wrote: Hi guys MRTG is having problems with timeshift because crond starts before chronyd on SL7. I have added chrond.service as a dependancy to the crond.service. Is that the right approach to solving the problem? This sounds like the right approach. But systemd have different levels of dependencies. I recommend you to check the dependency you used against man systemd.unit. Check out After=, Requires= and Requisite=. -- kind regards, David Sommerseth
RE: SL7 - crond starting before chronyd causing problem with mrtg
Thanks David. However, even using After= chronyd.service the chronyd still takes too long to correct the time for the time-zone. After some investigation, it seems that the KVM system is at fault when the host is rebooted, but not when the guest is rebooted. On reboot of the host KVM adds the timezone shift to the hardware clock for the guests and then the guest adds the timezone shift again. This extra addition of the timzone shift did not happen on SL6. After running hwclock --systohc on the guest, I get the following setup. [root@giggs2 ~]# timedatectl Local time: Thu 2015-01-22 17:55:26 AEDT Universal time: Thu 2015-01-22 06:55:26 UTC RTC time: Thu 2015-01-22 06:55:26 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ~]# On reboot of just the guest, I get the following, the RTC looks OK: [root@giggs2 ~]# timedatectl Local time: Thu 2015-01-22 18:05:09 AEDT Universal time: Thu 2015-01-22 07:05:09 UTC RTC time: Thu 2015-01-22 07:05:09 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ~]# On reboot of the host, I get the following on the guest, the RTC looks wrong: [root@giggs2 ~]# timedatectl Local time: Fri 2015-01-23 05:15:41 AEDT Universal time: Thu 2015-01-22 18:15:41 UTC RTC time: Thu 2015-01-22 18:15:42 Timezone: Australia/Sydney (AEDT, +1100) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2014-10-05 01:59:59 AEST Sun 2014-10-05 03:00:00 AEDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2015-04-05 02:59:59 AEDT Sun 2015-04-05 02:00:00 AEST [root@giggs2 ~]# Regards Bill Maidment -Original message- From:David Sommerseth sl+us...@lists.topphemmelig.net Sent: Wednesday 21st January 2015 23:33 To: Bill Maidment b...@maidment.me; SCIENTIFIC-LINUX-USERS@FNAL.GOV SCIENTIFIC-LINUX-USERS@fnal.gov Subject: Re: SL7 - crond starting before chronyd causing problem with mrtg On 21/01/15 12:18, Bill Maidment wrote: Hi guys MRTG is having problems with timeshift because crond starts before chronyd on SL7. I have added chrond.service as a dependancy to the crond.service. Is that the right approach to solving the problem? This sounds like the right approach. But systemd have different levels of dependencies. I recommend you to check the dependency you used against man systemd.unit. Check out After=, Requires= and Requisite=. -- kind regards, David Sommerseth
Re: SL7 - crond starting before chronyd causing problem with mrtg
On 21/01/15 12:18, Bill Maidment wrote: Hi guys MRTG is having problems with timeshift because crond starts before chronyd on SL7. I have added chrond.service as a dependancy to the crond.service. Is that the right approach to solving the problem? This sounds like the right approach. But systemd have different levels of dependencies. I recommend you to check the dependency you used against man systemd.unit. Check out After=, Requires= and Requisite=. -- kind regards, David Sommerseth
