Hello oVirt guru`s! I want to configure Kerberos authentication (via MS Active Directory) for the oVirt portal. So I need to properly configure the time synchronization for my Hosted Engine VM. I set up chronyd service in a HE VM for time synchronization from Active Directory domain controllers: # cat /etc/chrony.conf | grep ^[^#\;] server 10.1.0.9 iburst server 10.1.6.8 iburst stratumweight 0 driftfile /var/lib/chrony/drift rtcsync makestep 10 3 bindcmdaddress 127.0.0.1 keyfile /etc/chrony.keys commandkey 1 generatecommandkey noclientlog logchange 0.5 logdir /var/log/chrony # chronyc tracking Reference ID : 10.1.0.9 (kom-dc01.holding.com) Stratum : 4 Ref time (UTC) : Mon Sep 26 17:40:16 2016 System time : 0.000437915 seconds slow of NTP time Last offset : -0.000789918 seconds RMS offset : 0.001730987 seconds Frequency : 13.612 ppm slow Residual freq : -0.009 ppm Skew : 0.166 ppm Root delay : 0.078126 seconds Root dispersion : 0.126046 seconds Update interval : 1031.9 seconds Leap status : Normal It looks workable. But I think that the service may conflict with the kvm-clock # cat /sys/devices/system/clocksource/clocksource0/current_clocksource kvm-clock # dmesg | grep -i clock [ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00 [ 0.000000] kvm-clock: cpu 0, msr 2:3ff84001, primary cpu clock [ 0.000000] kvm-clock: using sched offset of 6567130420 cycles [ 0.538339] kvm-clock: cpu 1, msr 2:3ff84041, secondary cpu clock [ 0.571323] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI] [ 0.663452] Switching to clocksource kvm-clock [ 1.065348] rtc_cmos 00:00: setting system clock to 2016-09-25 16:16:04 UTC (1474820164) [ 1.988543] tsc: Refined TSC clocksource calibration: 3166.733 MHz [ 16.792347] Adjusting kvm-clock more than 11% (9437295 vs 9311354) Do I need to turn off kvm-clock in virtual machine properties? And how to do it? Please explain the best practice.