Cannot Synchronize NTP Time for Centos 6.2 VM running under Proxmox 2.1

[Scott Alden]

I've been unable to synchronize my CentOS 6.2 VM's running under Proxmox 2.1 using NTP. I've updated the systems using ntpdate to get them up to date, and then running ntpd to keep them in sync, but they've so far been unable to achieve synchronization.

I've gone through all the troubleshooting I can find on NTP with no luck (I'm successfully running NTP on 12 different VMs under Proxmox 1.9 - this only seems like a problem on 2.1 as far as I can tell)

Anyone having the same trouble care to enlighten?

 

[e100]

Why not just run NTP on Proxmox and let it provide the right time to the guests?

 

[Scott Alden]

I didn't realize this was possible, after checking it, the Proxmox time is pretty far off despite it running NTP out of the box - doesn't appear it's syncing either, and I have verified that port 123 is open.

 

[e100]

I setup two Proxmox servers to sync to each other along with two servers from ntp.org pool and two servers from NIST.
All other servers, including other Proxmox nodes, sync time to the first two servers.

Works great.

The only time I have had issues with NTP not syncing was because a firewall was blocking it somewhere.
NTP uses UDP port 123, maybe the firewall was accidentally set to allow TCP 123?