Andrew Latham

On systems like Debian Stretch with systemd the time sync is baked in but will not run if the legacy NTP package is installed at all so here is a howto/demo of what to do.

# apt-get purge ntp
# systemctl restart systemd-timesyncd.service
# systemctl status systemd-timesyncd.service 
● systemd-timesyncd.service - Network Time Synchronization
   Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
  Drop-In: /lib/systemd/system/systemd-timesyncd.service.d
           └─disable-with-time-daemon.conf
   Active: active (running) since Fri 2017-08-11 10:09:11 CDT; 3s ago
     Docs: man:systemd-timesyncd.service(8)
 Main PID: 31413 (systemd-timesyn)
   Status: "Synchronized to time server 92.243.6.5:123 (0.debian.pool.ntp.org)."
    Tasks: 2 (limit: 4915)
   CGroup: /system.slice/systemd-timesyncd.service
           └─31413 /lib/systemd/systemd-timesyncd

Aug 11 10:09:11 nodeone systemd[1]: Starting Network Time Synchronization...
Aug 11 10:09:11 nodeone systemd[1]: Started Network Time Synchronization.
Aug 11 10:09:11 nodeone systemd-timesyncd[31413]: Synchronized to time server 92.243.6.5:123 (0.debian.pool.ntp.org).
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Andrew Latham

Clean installs directly from the repos...

Using libvirt (virsh/virt-install/virt-manager) you can install from the HTTP repo of a Linux distribution to be super lazy. During installation you simply provide the URI in the location field or tools like virt-manager will have an option in the wizard.

For Debian you would use:

http://deb.debian.org/debian/dists/stable/main/installer-amd64/

For CentOS which lacks a CDN mirror or I could not find it quickly, you can try:

http://mirrors.kernel.org/centos/7/os/x86_64/