On 04/21/2017 09:25 AM, Denniston, Todd A CIV NAVSURFWARCENDIV Crane, JXVS wrote: > ________________________________________ > From: Robert Moskowitz [rgm at htt-consult.com] > Sent: Thursday, April 20, 2017 5:00 PM > To: CentOS mailing list > Subject: [CentOS] What besides Postfix should not start until system time set? >> So I have learned that Postfix should delay until Chronyd has moved the >> system time from 0 to current. > Something you might consider to make the time delta _less_ drastic, is to create a service which on system shutdown touches a file {in /etc/} and on boot early in the start-up {make some other services depend on it} checks to see if the system date&time is before the time on that file, if it is then use the time stamp {+ a few sec} on the file to set the current time. That way time would at least move forward. > > in the olden days we used to use `hwclock --badyear` mitigate part of it. perhaps you could extend hwclock for --dead-batteries and make it easier for every one with an arm {assuming hwclock is still used in the boot process to pull the initial time from the clock}. :) > > Even when this disclaimer is not here: > I am not a contracting officer. I do not have authority to make or modify the terms of any contract. Miroslav has been a great help over on the chronyd list. I have learned to add the -s option to chronyd and point the rtcdevice to nothing so that the Centos version of Chronyd, 2.1.1, will read the timestamp from the driftfile if no ntp respose: cat <<EOF>/etc/sysconfig/chronyd || exit 1 OPTIONS=" -s" EOF cat <<EOF>>/etc/chrony.conf || exit 1 rtcdevice /dev/doesnotexist EOF With chronyd 2.2, you only need the "-s" option.