chrony operation
ntpq
chronyc sources
amazon linux default config
/etc/chrony.conf
# use the local instance NTP service, if available
server 169.254.169.123 prefer iburst
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
pool 2.amazon.pool.ntp.org iburst
# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift
# Allow the system clock to be stepped in the first three updates
# if its offset is larger than 1 second.
makestep 1.0 3
# Allow NTP client access from local network.
#allow 192.168.0.0/16
# Specify file containing keys for NTP authentication.
keyfile /etc/chrony.keys
# Specify directory for log files.
logdir /var/log/chrony
# Select which information is logged.
#log measurements statistics tracking
# save data between restarts for fast re-load
dumponexit
dumpdir /var/run/chrony
# use a key to secure communication between chronyc and the daemon
commandkey key1
Support leap-sec ???
Default, NO but...
leapsecmode directive
- Maybe from ver > 2.x.
- RHEL7(cent7) updated to 2.1 https://www.scientificlinux.org/sl-errata/slsa-20152241-3/
- RHEL6(cent6) + EPEL ???
leapsecmode slew
maxslewrate 1000
smoothtime 400 0.001 leaponly
Verification
Confirmed