On 04/22/2017 07:43 PM, Jim Perrin wrote: > > On 04/21/2017 06:03 AM, Robert Moskowitz wrote: >> Fellow armv7-without-rtc-battery users. Maybe you have already learned >> this, but I THINK I have completed my education on this thanks to >> Miroslav Lichvar on the Chrony list. >> >> There are two issues here: It takes time for chronyd to set the system >> time. And if it fails to reach the ntp servers, well, it failed to set >> the time. >> >> For the first, we need to delay some services from starting until >> chronyd is successful. Postfix is one of them. So we need the >> following commands: >> >> systemctl enable chrony-wait >> systemctl start chrony-wait >> sed -i '/^After=/ s/$/ time-sync.target/w /dev/stdout' >> /usr/lib/systemd/system/postfix.service >> > You're not going to want to do this here. Because systemd has a concept > of overrides, administrator modifications should go in > /etc/systemd/system, rather than directly modifying /usr/lib/systemd/* > files. This will keep your changes across updates. I did not like changing postfix.service, but I have not found how to modify the After= instructions through /etc/systemd/system. Can you point me to instructions? I looked at /etc/systemd/system/multi-user.target.wants/postfix.service And the change I made to /usr/lib/systemd/system/postfix.service carried over, and the timestamp in /etc/systemd did not change. Strange. thanks > >> There are some possible instances where you also want to do this to >> httpd.service, but I have been advised on the postfix list NOT to run >> postfix if the systemtime is earlier than the postfix build date >> >> $ postconf -dh mail_release_date >> 20130622 >> >> Plus the postfix.service runs aliases.db which will mess up your >> aliases.db timestamp. >> >> Next there is that pesky issue about what if no ntp servers reached? >> >> First: >> >> cat <<EOF>/etc/sysconfig/chronyd || exit 1 >> OPTIONS=" -s" >> EOF >> >> Since Centos7 has Chronyd 2.1.1, not 2.2, we have extra work to do in >> chronyd.conf: >> >> cat <<EOF>>/etc/chrony.conf || exit 1 >> rtcdevice /dev/doesnotexist >> EOF >> >> >> I am adding this to my basic server howto page. >> >> >> _______________________________________________ >> Arm-dev mailing list >> Arm-dev at centos.org >> https://lists.centos.org/mailman/listinfo/arm-dev