Quillyn Posted January 19, 2014 Posted January 19, 2014 The problem: My only domain controller time keeps jumping either forwards or backwards a amount between 2 hours and 24 hours. Background I run 4 virtual 2008r2 servers and one physical, all connected to the domain. The virtual servers run on VMware across two machines. The setup has been pretty static for the last 6 months. The time across the domain started jumping a few days ago. Currently I have no access to a ntp server (a separate issue with over zealous county blocking, that is taking them months to fix) Attempted fixes Played around with w32tm, all domain machines were resyncing to domain. Domain had no w32tm host/ source listed to resync from. Disabled w32tm on the domain server- this caused all the network machines other than 2008r2 to retain the correct time. Now though each of 2008r2 servers will be running at different times. Over night one server gained 7 hours another gained 2 days while the antivirus server lost a month. At first I thought this might be to do with only the virtualised machines but the lone physical server had the same issue. Questions Any ideas what is setting the time for the 2008r2 machines? Can anyone suggest a tool to pinpoint whats setting the time seemingly randomly. I tried a tool called ntplookup but it could not identify any rogue ntp servers. Am I missing something obvious?
kmount Posted January 19, 2014 Posted January 19, 2014 Is your domain controller virtual or physical? I've seen instances where if the host time (VMware hypervisor) is wrong then the guests pick up from this which helps to explain big jumps. If the domain controller is the physical server it's likely not relevant.
twin--turbo Posted January 19, 2014 Posted January 19, 2014 even if you don't have true internet time I would have a fixed time reference in the building. Build a basic Linux box with NTPD and use that. Rob 1
Quillyn Posted January 19, 2014 Author Posted January 19, 2014 The domain controller is virtual. The host time also changes but not always the same as the domain server. Example Domain server +3 hours, host server still retaining the correct time, physical server lost 4 hours.
Quillyn Posted January 19, 2014 Author Posted January 19, 2014 even if you don't have true internet time I would have a fixed time reference in the building. Build a basic Linux box with NTPD and use that. Rob I have been considering building my own time server, but I am concerned that this unknown time changing issue may still occur. Any advice on the quickest/ easiest build to go for?
glennda Posted January 19, 2014 Posted January 19, 2014 In VSphere client - right click server edit settings, Options, VMware Tools, on the bottom left does it have Syncronise Guest time with host ticked? 1
kmount Posted January 19, 2014 Posted January 19, 2014 If the hypervisor time is jumping too, is it pointing to something else for time? (and that it may be is the one jumping). As twin--turbo said, even without NTP you should have a fixed time source internally so your stuff is in sync with each other, not necessarily the rest of the world but for most things that is fine. Would be useful to know what the hypervisors are doing for their time configuration, it could be the root of the problem. Also worth checking timezone configured on your server builds just incase, that can account for 'big hour' jumps. 1
Arthur Posted January 19, 2014 Posted January 19, 2014 Domain had no w32tm host / source listed to resync from. All you should need to do is configure the time on the server which holds the PDC emulator role so that it syncs with an external source. The other servers in your domain will automatically find the authoritative time server and sync with that. Configure an Active Directory authoritative time source « Binary Nature How to configure "Authoritative Time server" in an AD domain 1
Quillyn Posted January 19, 2014 Author Posted January 19, 2014 In VSphere client - right click server edit settings, Options, VMware Tools, on the bottom left does it have Syncronise Guest time with host ticked? I will have to check when back on site (just been kicked out). I believe they are not set to Synchronize guest time. If the hypervisor time is jumping too, is it pointing to something else for time? (and that it may be is the one jumping). Would be useful to know what the hypervisors are doing for their time configuration, it could be the root of the problem. Also worth checking timezone configured on your server builds just incase, that can account for 'big hour' jumps. The VMware hosts and both joined to the domain and were taking their time from the domain controller. They are no longer set to pick up time the ntp client is stopped, yet they still change at the same rate as the 2008r2 servers. All the servers and hosts are set to London time zones (was one of my early thoughts too).
kmount Posted January 19, 2014 Posted January 19, 2014 Hang on, that makes some sense. If the hosts are taking time from a VM that is running on one of them that could explain some of the jumping around if the real time clock (rtc) on the hosts themselves is off. Look in the BIOS on the vmware hosts and see what they're on, they will boot with that time (and then change / sync to the configured one). 1
Quillyn Posted January 19, 2014 Author Posted January 19, 2014 That could well be it, a odd feedback time loop, thanks allot gives me something to look in to.
kmount Posted January 19, 2014 Posted January 19, 2014 No worries, good luck, will be interested in the outcome!
Quillyn Posted January 20, 2014 Author Posted January 20, 2014 Darn.. I checked the BIOS of one of our VMware hosts and the time was spot on. I can confirm that time sync between the virtual servers and the ESX server is presently unticked. In noted behavior since I left yesterday.. All virtual servers and hosts had changed to 17.12.2005 The physical server had the right time. 1 hour later Both hosts were using 23.02.2022 2/4 servers were using 23.02.2022 including the domain server The other two servers were displaying the correct time. Physical server had the correct date/ time
Michael Posted January 20, 2014 Posted January 20, 2014 To set the time server on 2008 R2, run the following command on a physical DC (recommended): @echo off net stop w32time w32tm /config /syncfromflags:manual /manualpeerlist:ntp.bgfl.org w32tm /config /reliable:yes net start w32time w32tm /query /peers PAUSE Just change the name of the NTP server to your time server of choice. If your LA are unable to provide a suitable NTP server, you should request port UDP 123 is unblocked or at least forwarded to a nominated time server. Without this I bet your local network is creating a whole range of errors disrupting users.
Quillyn Posted January 20, 2014 Author Posted January 20, 2014 Okay I think I have a solution I set up a internal ntp server and pointed the VMware hosts to it, yet their times where still jumping to 2005. So I have removed the VMware host from the domain, and set the virtual machines to pick up time from the VMhosts, the VWware host pick up time from my local ntp server. Not a great solution but seems to be working presently
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