Unmanaged VDS time drift

[Xinux]

Is it normal to have a 20 second time drift every half a hour? I have the server updating the time every 1/2 a hour cause if I didn't the time jump would
be to great and have a negative effect on my services that 20 seconds isn't helping either but manageable currently.

I have it syncing to time-a.nist.gov

10:54:59 AM
The system time has changed to ‎2017‎-‎01‎-‎19T18:54:59.345168800Z from ‎2017‎-‎01‎-‎19T18:54:39.300061500Z.

11:24:59 AM
The system time has changed to ‎2017‎-‎01‎-‎19T19:24:59.291800300Z from ‎2017‎-‎01‎-‎19T19:24:39.314221600Z.

11:54:59 AM
The system time has changed to ‎2017‎-‎01‎-‎19T19:54:59.285459900Z from ‎2017‎-‎01‎-‎19T19:54:39.329806000Z.

[Edge100x]

That's definitely not normal and suggests that your kernel may not be using an accurate clock source. This should not happen if it is using TSC or HPET.

What OS are you running?

[Xinux]

Windows Server 2012 R2

[Xinux]

Look's like HPET is there but no drivers. Been doing some reading and everything I've read so far seem to lean toward using TSC over HPET anyway but personally I've never messed with either option.

[Edge100x]

It's odd that Windows 2012 R2 wouldn't be using TSC out of the box.

I recommend that you try disabling HPET through the "Server control" page of the control panel (under advanced options) to see if that helps.

[Xinux]

Unchecked it then set advanced options then rebooted the VDS. It's still listed in the device manager but i'll see how it does over the next few hours.

[Edge100x]

Did you reboot your VDS through the control panel or from inside the VDS? You would need to do it through the control panel. Or, turn off the VDS from inside the OS, then turn it back on through the control panel.

[Xinux]

Ok that worked shut it down then turned on from the control panel. I'll let you know tomorrow how the time drift look's.

[Xinux]

Well that is a little better only off by 12 seconds now every 30 minutes.

The system time has changed to ‎2017‎-‎01‎-‎20T02:40:11.706567900Z from ‎2017‎-‎01‎-‎20T02:39:59.457402800Z.

The system time has changed to ‎2017‎-‎01‎-‎20T03:10:11.722935700Z from ‎2017‎-‎01‎-‎20T03:09:59.476151900Z.

[Edge100x]

That's still not good, no question about it. Very odd.

[Xinux]

Well i'm open to suggestion to what to try next. I wonder if anyone else is also getting this bad of a drift but there applications don't require timing as much as mine.

[Xinux]

Here is the config for it.

configuration

Code: Select all

C:\Users\Administrator>w32tm /query /configuration /verbose
[Configuration]

EventLogFlags: 2 (Local)
AnnounceFlags: 5 (Local)
TimeJumpAuditOffset: 28800 (Local)
MinPollInterval: 10 (Local)
MaxPollInterval: 15 (Local)
MaxNegPhaseCorrection: 3600 (Local)
MaxPosPhaseCorrection: 3600 (Local)
MaxAllowedPhaseOffset: 1 (Local)

FrequencyCorrectRate: 4 (Local)
PollAdjustFactor: 5 (Local)
LargePhaseOffset: 50000000 (Local)
SpikeWatchPeriod: 900 (Local)
LocalClockDispersion: 10 (Local)
HoldPeriod: 5 (Local)
PhaseCorrectRate: 1 (Local)
UpdateInterval: 900 (Local)

FileLogName:  (Undefined or NotUsed)
FileLogEntries:  (Undefined or NotUsed)
FileLogSize: 0 (Undefined or NotUsed)
FileLogFlags: 0 (Undefined or NotUsed)

[TimeProviders]

NtpClient (Local)
DllName: C:\Windows\system32\w32time.dll (Local)
Enabled: 1 (Local)
InputProvider: 1 (Local)
CrossSiteSyncFlags: 0 (Undefined or NotUsed)
AllowNonstandardModeCombinations: 1 (Local)
ResolvePeerBackoffMinutes: 15 (Local)
ResolvePeerBackoffMaxTimes: 7 (Local)
CompatibilityFlags: 2147483648 (Local)
EventLogFlags: 1 (Local)
LargeSampleSkew: 3 (Local)
SpecialPollInterval: 900 (Local)
Type: NTP (Local)
NtpServer: time-a.nist.gov,0x9 (Local)

VMICTimeProvider (Local)
DllName: C:\Windows\System32\vmictimeprovider.dll (Local)
Enabled: 1 (Local)
InputProvider: 1 (Local)
NtpServer (Local)
DllName: C:\Windows\system32\w32time.dll (Local)
Enabled: 0 (Local)
InputProvider: 0 (Local)

status

Code: Select all

C:\Users\Administrator>w32tm /query /status /verbose
Leap Indicator: 0(no warning)
Stratum: 2 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.0000000s
Root Dispersion: 10.0000000s
ReferenceId: 0x81060F1C (source IP:  129.6.15.28)
Last Successful Sync Time: 1/20/2017 8:55:05 AM
Source: time-a.nist.gov,0x9
Poll Interval: 10 (1024s)

Phase Offset: 0.0000000s
ClockRate: 0.0156250s
State Machine: 0 (Unset)
Time Source Flags: 0 (None)
Server Role: 576 (Reliable Time Service)
Last Sync Error: 1 (The computer did not resync because no time data was availab
le.)
Time since Last Good Sync Time: 1212.7345418s

peers

Code: Select all

C:\Users\Administrator>w32tm /query /peers /verbose
#Peers: 1

Peer: time-a.nist.gov,0x9
State: Active
Time Remaining: 608.5356051s
Mode: 3 (Client)
Stratum: 0 (unspecified)
PeerPoll Interval: 10 (1024s)
HostPoll Interval: 10 (1024s)
Last Successful Sync Time: 1/20/2017 8:55:05 AM
LastSyncError: 0x00000000 (Succeeded)
LastSyncErrorMsgId: 0x00000000 (Succeeded)
AuthTypeMsgId: 0x0000005A (NoAuth )
Resolve Attempts: 0
ValidDataCounter: 8
Reachability: 86

[Xinux]

Here is a little more info I've turn off time synch for now and just watching the windows clock I can see it stutter every minute to a minute and 1/2 for a second and that is when the windows time fall's behind.

[Xinux]

Cpu is around 10% and not spiking and ram is steady so don't think it's a load issue.

[Edge100x]

I've never heard of or seen reports of stuttering from other customers, and I definitely would expect to have heard of that, since game servers (which most of our customers run) are highly sensitive to such things and it would kill gameplay. That suggests that whatever is happening may be unique to your configuration.

If a client has personal packet loss, remote desktop is known to hiccup and cause problems for the machine. Does this happen even when you're not connected to remote desktop?

I don't have many other suggestions for things you could try, since we don't have many other knobs we can turn on this end. When it comes to timekeeping, we run a stock Xen configuration, and a stock Windows configuration, and there just aren't many adjustments that can be made in Xen.