I've got a Windows Server 2008 R2 Datacenter instance running as a VM on Citrix XenServer 6.0.2. This server is joined to a 2003-level AD domain and is in the same subnet as the domain. The server's system clock keeps rolling backwards as I watch in real-time. I can re-synchronize with the domain, and NTP source, manually set the clock but it will start rolling backwards as I'm watching it. The DC has no time issues, nor do any other joined servers. The virtual host has no time issues, nor do any other VMs on that host. I have no errors in the event log and nothing to indicate why this is happening. It appears to have started on 7/29 based on when the last SQL job ran. I have no idea what is happening, have never seen nor heard anything like it. It doesn't matter if I sync using net time, win32tm, or the clock application. It will start rolling backwards about 5-10 minutes every 5 seconds or so. Any ideas? I rebooted the server and it is now stable, but I'd still like to know what happened if anyone has any ideas.

Hi, Any of the following citrix KBs should help How to Set Up an NTP Server for a XenServer Network http://support.citrix.com/article/CTX116307/ How to Configure and Test Time Using the Network Time Protocol on XenServer http://support.citrix.com/article/CTX116458/ How to Change NTP Source on XenServer 5.0 http://support.citrix.com/article/CTX121278/ You might also get more help in Citrix Forums Knowledge Center> Support Forums > XenServer > XenServer/Essentials Product Family > Server Installation http://forums.citrix.com/forum.jspa;jsessionid=EA97253CC49B4496A72E05AFD9A2BA14?forumID=503&start=0 I do not represent the organisation I work for, all the opinions expressed here are my own. This posting is provided "AS IS" with no warranties or guarantees and confers no rights. - .... .- -. -.- ... --..-- ... .- -. - --- ... ....

Hi, I am glad to hear that the time is stable now. You may check the event logs for the possible cause of the issue. Regards,Arthur Li TechNet Community Support

Thank you, but the issue is not domain time. That has been set correctly since inception. The issue is that one server in the domain has it's system clock running backwards. I can watch the clock jump back several minutes over a 5 second span and it continues to go backwards even after re-synchronizing. I rebooted the server and it is now stable, but I'd still like to know what happened if anyone has any ideas.

Thank you, but the issue has nothing to do with XenServer. The XenServer host has NTP enabled and is synchronizing with the same NTP source as our domain. There are no issues with time on that host or any other guests on that host, only on this one server where time continuously goes backwards. I rebooted the server and it is now stable, but I'd still like to know what happened if anyone has any ideas.