Guest Brian McCauley Posted April 29, 2008 Posted April 29, 2008 I have a number of Windows member servers in an AD forrest and in steady state w32time keeps there clocks approximately right (+-200ms). However when they are rebooted their clocks are (for a short time) all over the place (for 10-30 minutes) because, it would appear, that nothng is keeping the CMOS (non-volatile harware) clock in sycronisation with the Windows clock. On Linux I'd just create a cron job to do "clock -uw" periodically but I can't find any equivalent on Windows. Please note: I'm asking how to get Windows to keep the *CMOS* clock synced so that when servers are rebooted their clocks start out *approximately* right *before* w32time manages to syncronise to a time server.
Guest Pegasus \(MVP\) Posted April 29, 2008 Posted April 29, 2008 Re: CMOS (non-volatile harware) clock sycronisation "Brian McCauley" <my-name-with-a-dot-in-it@uhb.nhs.uk.invalid> wrote in message news:E7523F1F-9CBF-44A0-9DFE-71C85C8E5F49@microsoft.com... >I have a number of Windows member servers in an AD forrest and in steady > state w32time keeps there clocks approximately right (+-200ms). However > when > they are rebooted their clocks are (for a short time) all over the place > (for > 10-30 minutes) because, it would appear, that nothng is keeping the CMOS > (non-volatile harware) clock in sycronisation with the Windows clock. > > On Linux I'd just create a cron job to do "clock -uw" periodically but I > can't find any equivalent on Windows. > > Please note: I'm asking how to get Windows to keep the *CMOS* clock synced > so that when servers are rebooted their clocks start out *approximately* > right *before* w32time manages to syncronise to a time server. Sounds like you need to replace a few motherboard batteries. They cause the time to go out while your machines are turned off.
Guest Brian McCauley Posted April 29, 2008 Posted April 29, 2008 Re: CMOS (non-volatile harware) clock sycronisation "Pegasus (MVP)" wrote: > "Brian McCauley" <my-name-with-a-dot-in-it@uhb.nhs.uk.invalid> wrote in > > .... rebooted their clocks are (for a short time) all over the place > > (for 10-30 minutes) because, it would appear, that nothng is keeping the CMOS > > (non-volatile harware) clock in sycronisation with the Windows clock. > > Sounds like you need to replace a few motherboard batteries. They > cause the time to go out while your machines are turned off. This happens on serveral servers that are only a few years old and the effect is not dependant on the machines being turned off so I think I can rule out the batteries as being the cause.
Guest stephen.tompsett@gmail.com Posted June 10, 2008 Posted June 10, 2008 Re: CMOS (non-volatile harware) clock sycronisation On Apr 29, 4:46 pm, Brian McCauley <my-name-with-a-dot- in...@uhb.nhs.uk.invalid> wrote: > "Pegasus (MVP)" wrote: > > "Brian McCauley" <my-name-with-a-dot-in...@uhb.nhs.uk.invalid> wrote in > > > .... rebooted their clocks are (for a short time) all over the place > > > (for 10-30 minutes) because, it would appear, that nothng is keeping the CMOS > > > (non-volatile harware) clock in sycronisation with the Windows clock. > > > Sounds like you need to replace a few motherboard batteries. They > > cause the time to go out while your machines are turned off. > > This happens on serveral servers that are only a few years old and the > effect is not dependant on the machines being turned off so I think I can > rule out the batteries as being the cause. I have a similar problem with Compaq/HP server hardware that is working according to specification - The hardware clock drifts at approximately 1 second a day if uncorrectrd. Using Windows 2000 I synchronise to an NTP server, but have specified the maximum time correction allowed as 60 seconds, When the server is rebooted the time is corrected, until it has been running long enough for the time correction required is greater than 60 seconds, at which time it requires manual correction to allow it to synchronise. It appears that the CMOS time is not adjusted to the corrected system time by the normal operation of W32TIME.
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