Re: Time quandry when dual boot with WinXP Pro
On Saturday 29 October 2016 16:29:11 Felix Miata wrote: > Lisi Reisz composed on 2016-10-29 15:44 (UTC+0100): > > Windows uses local time for the hardware clock, Linux uses UTC. > > By default, yes, but not necessarily: > https://wiki.archlinux.org/index.php/time#UTC_in_Windows Ah! It is a very long time since I used Windows and I had not remembered how I used to deal with it. Lisi
Re: Time quandry when dual boot with WinXP Pro
Lisi Reisz composed on 2016-10-29 15:44 (UTC+0100): Windows uses local time for the hardware clock, Linux uses UTC. By default, yes, but not necessarily: https://wiki.archlinux.org/index.php/time#UTC_in_Windows -- "The wise are known for their understanding, and pleasant words are persuasive." Proverbs 16:21 (New Living Translation) Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata *** http://fm.no-ip.com/
Re: Time quandry when dual boot with WinXP Pro
On Friday 21 October 2016 14:09:38 Richard Owlett wrote: > I'm creating a preseed.cfg file for installing Debian 8.6 in a > dual-boot enviroment with some version of MS Windows. There are > two distinct use cases: > 1. Two of my machines with WinXP Pro SP3 > 2. A remote (~1000 miles]friend with several machines - some > with WinXP, others with >Windows 10 or later. > > I have discovered on my WinXP machine that: > 1. WinXP _displays_ the correct time. >"Date and Time Properties" - Time Zone set to >(GMT-06:00)Central Time(US) >Automatically adjust clock for daylight saving changes > 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct > time > 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of > custom preseed.cfg >_displays_ a time 5 hours earlier. >The _display_ is independent of whether > d-i clock-setup/utc boolean true > *OR* > d-i clock-setup/utc boolean false >is used in the preseed.cfg file. > > I'm confused. Windows uses local time for the hardware clock, Linux uses UTC. The Live CD presumably uses its common sense when looking at the machine on which it is required to run. I don't know. I am not familiar with the Live CD. You are presumably at GMT-5, hence displaying 5 hours earlier on the assumption that your hardware clock is set to UTC. Lisi
[REPOST] Re: Time quandry when dual boot with WinXP Pro
On 10/22/2016 3:15 PM, Stefan Monnier wrote: 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. My guess: the Live DVD uses NTP so as not to depend on the hwclock whereas your installs don't. As the saying goes, "that does not compute". The machine in question has not been connected to the internet, or any other network, for several years ;/ Simple: over all these years its lust for a network connection was so strong that it managed to find a way to get to the Internet. Stefan You may have identified the problem after all ;/ What might the side effects of specifying use of NTP on installation be? Is there something I can tweak in the *installed* system to duplicate what would have been done if the use of NTP had been specified in preseed.cfg? Even given an affirmative answer to above, I can do a complete reinstall to assist in tracking possible side effects -- there is no valuable data on that machine.
Side effects of specifying use of NTP on installation???? - was [Re: Time quandry when dual boot with WinXP Pro]
On 10/22/2016 3:15 PM, Stefan Monnier wrote: 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. My guess: the Live DVD uses NTP so as not to depend on the hwclock whereas your installs don't. As the saying goes, "that does not compute". The machine in question has not been connected to the internet, or any other network, for several years ;/ Simple: over all these years its lust for a network connection was so strong that it managed to find a way to get to the Internet. Stefan You may have identified the problem after all ;/ What might the side effects of specifying use of NTP on installation be? Is there something I can tweak in the *installed* system to duplicate what would have been done if the use of NTP had been specified in preseed.cfg? Even given an affirmative answer to above, I can do a complete reinstall to assist in tracking possible side effects -- there is no valuable data on that machine.
Re: Time quandry when dual boot with WinXP Pro
On Sat 22 Oct 2016 at 16:42:57 (+0100), Joe wrote: > On Sat, 22 Oct 2016 09:57:05 -0500 > David Wrightwrote: > > > On Fri 21 Oct 2016 at 18:47:43 (+0100), Joe wrote: > > > On Fri, 21 Oct 2016 09:58:42 -0500 > > > David Wright wrote: > > > > > > > > . Neither OS was running when Civil Time changed to/from DST, > > > > . After the time changed, one OS has run, updating the Local Time > > > > to match Civil Time, . Another OS is just being booted up. > > > > > > > > What Local Time will eventually be displayed by this system? > > > > > > > DST may well be the answer. > > > > (I can't see how that answers anything, as I hadn't specified which > > way time changed, nor can I see why it would be an answer in either > > case.) > > It is *a* reason for inter-OS time shifting, it may be applicable to > your or other peoples' cases. > > > > My concern is that the second OS to boot might apply the time change > > in exactly the same manner as the first one did and should have done. > > So the system's Local Time would end up an hour fast (were this late > > Spring) or slow (were this late Fall) after the second OS applied its > > own time change. > > > > Or IOW what mechanism is there for one OS to find out whether another > > OS has altered the RTC by an hour any time recently?¹ > > > > > If I boot Linux on my Win8 laptop in the > > > summer, it knows the time perfectly well. If I now boot Win8, the > > > clock is an hour ahead. It does use a network time source but it > > > does not query the source on boot, or soon afterwards. Eventually > > > it will do so, but on a fixed schedule, so not for days, and there > > > seems to be no way to fix it. It's not just the first time after > > > DST arrives, it's every time. > > > > But isn't that just a configuration problem which I assume is unusual > > in that most people are not reporting that problem? What's more, you > > don't say whether your RTC is running UTC or some other time. > > > > Ignoring drift, a RTC running UTC never changes, so the hardware > > always knows the correct time. The Local Time displayed is just a > > matter of sensible configuration. > > > > My question, posed above, is *only* of concern where the RTC is > > running non-UTC, ie it gets fiddled with twice a year. At these two > > times, the RTC could be subject to incorrect alterations by > > erroneously configured OSes, or even multiple OSes perfectly > > configured, but unaware of each other's actions. > > I'm making the point that it isn't just at the point of change of DST > that this happens, but at any time when DST is active. Both OSes use > network time updates routinely, not just when they think the clock is > wrong (how could they tell otherwise?). Ah, now I realise why I couldn't understand your first answer: we're discussing a different problem. You're talking about the static problem of getting linux and windows to interpret the RTC in a way that is compatible with each other. My question relates to the OP's situation with no networking/NTP, but where the static configuration problems have been solved (where you've not succeeded), but with the RTC running non-UTC. And my question relates to the dynamic situation on two Sunday mornings of the year. I can sum it up as: With multiple OSes booting at various times, which OS is going to change the RTC by an hour, and how is it to communicate that it has done so to all the other OSes present on the computer, in order to prevent each one thinking that it has to make that change because *it* has total responsibility for the RTC. The six bullet points were to make the scenario concrete. One OS has changed the RTC to the new Local Time. It didn't use NTP to lookup the time; it merely noted that the time change must have occurred since the last boot, say, a week ago. The computer is happy. Now we boot up a second OS which makes the same observation: "Hey, I need to update Local Time because everyone changed their clocks last weekend." Do you see the problem? I don't see how to avoid it if you don't run a computer with RTC on UTC. > The issue is that when I made the Linux installation, I told it that > the hardware clock should be set to UTC (the default), whereas the > Windows installation will always assume local time. I was under the impression that the solution (from Darac) was to set HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal to 0 or 1 in the registry. Do you do that? > The two OSes will > always be an hour out during the DST period, and if you're not in the > UTC time zone, there will be a further offset at all times. This has > always been an issue when dual-booting, when you would normally tell > Linux to consider the HW clock to use local time as a workaround. I have to admit that I don't know how linux treats the time changes when the RTC is on Local Time. Does it look at /etc/timezone and the calendar and make the
Re: Time quandry when dual boot with WinXP Pro
>>> 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time >>> 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom >>> preseed.cfg >>> _displays_ a time 5 hours earlier. >> My guess: the Live DVD uses NTP so as not to depend on the hwclock >> whereas your installs don't. > As the saying goes, "that does not compute". The machine in question has not > been connected to the internet, or any other network, for several years ;/ Simple: over all these years its lust for a network connection was so strong that it managed to find a way to get to the Internet. Stefan
Re: Time quandry when dual boot with WinXP Pro
On 10/22/2016 2:56 PM, Stefan Monnier wrote: 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. My guess: the Live DVD uses NTP so as not to depend on the hwclock whereas your installs don't. As the saying goes, "that does not compute". The machine in question has not been connected to the internet, or any other network, for several years ;/
Re: Time quandry when dual boot with WinXP Pro
>2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time >3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom > preseed.cfg > _displays_ a time 5 hours earlier. My guess: the Live DVD uses NTP so as not to depend on the hwclock whereas your installs don't. Stefan
Re: Time quandry when dual boot with WinXP Pro
On Sat, 22 Oct 2016 09:57:05 -0500 David Wrightwrote: > On Fri 21 Oct 2016 at 18:47:43 (+0100), Joe wrote: > > On Fri, 21 Oct 2016 09:58:42 -0500 > > David Wright wrote: > > > > > > . Neither OS was running when Civil Time changed to/from DST, > > > . After the time changed, one OS has run, updating the Local Time > > > to match Civil Time, . Another OS is just being booted up. > > > > > > What Local Time will eventually be displayed by this system? > > > > > DST may well be the answer. > > (I can't see how that answers anything, as I hadn't specified which > way time changed, nor can I see why it would be an answer in either > case.) It is *a* reason for inter-OS time shifting, it may be applicable to your or other peoples' cases. > > My concern is that the second OS to boot might apply the time change > in exactly the same manner as the first one did and should have done. > So the system's Local Time would end up an hour fast (were this late > Spring) or slow (were this late Fall) after the second OS applied its > own time change. > > Or IOW what mechanism is there for one OS to find out whether another > OS has altered the RTC by an hour any time recently?¹ > > > If I boot Linux on my Win8 laptop in the > > summer, it knows the time perfectly well. If I now boot Win8, the > > clock is an hour ahead. It does use a network time source but it > > does not query the source on boot, or soon afterwards. Eventually > > it will do so, but on a fixed schedule, so not for days, and there > > seems to be no way to fix it. It's not just the first time after > > DST arrives, it's every time. > > But isn't that just a configuration problem which I assume is unusual > in that most people are not reporting that problem? What's more, you > don't say whether your RTC is running UTC or some other time. > > Ignoring drift, a RTC running UTC never changes, so the hardware > always knows the correct time. The Local Time displayed is just a > matter of sensible configuration. > > My question, posed above, is *only* of concern where the RTC is > running non-UTC, ie it gets fiddled with twice a year. At these two > times, the RTC could be subject to incorrect alterations by > erroneously configured OSes, or even multiple OSes perfectly > configured, but unaware of each other's actions. I'm making the point that it isn't just at the point of change of DST that this happens, but at any time when DST is active. Both OSes use network time updates routinely, not just when they think the clock is wrong (how could they tell otherwise?). The issue is that when I made the Linux installation, I told it that the hardware clock should be set to UTC (the default), whereas the Windows installation will always assume local time. The two OSes will always be an hour out during the DST period, and if you're not in the UTC time zone, there will be a further offset at all times. This has always been an issue when dual-booting, when you would normally tell Linux to consider the HW clock to use local time as a workaround. > > > I give it a kick manually, which of course involves entering an > > admin password... > > which is the necessity we're trying to avoid. > > ¹ There's another similar concern should you have more than one OS > thinking it's responsible for measuring and taking account of clock > drift. Whether this is going to concern people who are rebooting OSes > all the time is moot. > For most computers, a second or two of clock drift won't matter, if network time is being used to reset it every few days or once per boot. I found plenty of people with this problem, and a few solutions. None of them worked, of course, this is the Internet. The brute force and ignorance answer is a script to force a network time update on Windows soon after boot, as Linux does, but it happens to me so rarely that I haven't yet worked up the enthusiasm. There's apparently no Windows configuration flag to do this, or at least not in 8. The laptop runs Windows pretty much all the time, but I occasionally visit an establishment with free public wifi. I won't use Windows on a network like that, so I have a Debian installation on a USB hard drive which I boot from on those occasions, which resets my hardware clock to UTC. This *is* the behaviour I want when booting my netbook from this drive, which I do more often, so there's no configuration which will keep the laptop happy. -- Joe
Re: Time quandry when dual boot with WinXP Pro
On Sat, 22 Oct 2016 09:57:05 -0500 David Wrightwrote: > On Fri 21 Oct 2016 at 18:47:43 (+0100), Joe wrote: > > On Fri, 21 Oct 2016 09:58:42 -0500 > > David Wright wrote: > > > > > > . Neither OS was running when Civil Time changed to/from DST, > > > . After the time changed, one OS has run, updating the Local Time > > > to match Civil Time, . Another OS is just being booted up. > > > > > > What Local Time will eventually be displayed by this system? > > > > > DST may well be the answer. > > (I can't see how that answers anything, as I hadn't specified which > way time changed, nor can I see why it would be an answer in either > case.) > > My concern is that the second OS to boot might apply the time change > in exactly the same manner as the first one did and should have done. > So the system's Local Time would end up an hour fast (were this late > Spring) or slow (were this late Fall) after the second OS applied its > own time change. > > Or IOW what mechanism is there for one OS to find out whether another > OS has altered the RTC by an hour any time recently?¹ > > > If I boot Linux on my Win8 laptop in the > > summer, it knows the time perfectly well. If I now boot Win8, the > > clock is an hour ahead. It does use a network time source but it > > does not query the source on boot, or soon afterwards. Eventually > > it will do so, but on a fixed schedule, so not for days, and there > > seems to be no way to fix it. It's not just the first time after > > DST arrives, it's every time. > > But isn't that just a configuration problem which I assume is unusual > in that most people are not reporting that problem? What's more, you > don't say whether your RTC is running UTC or some other time. > > Ignoring drift, a RTC running UTC never changes, so the hardware > always knows the correct time. The Local Time displayed is just a > matter of sensible configuration. > > My question, posed above, is *only* of concern where the RTC is > running non-UTC, ie it gets fiddled with twice a year. At these two > times, the RTC could be subject to incorrect alterations by > erroneously configured OSes, or even multiple OSes perfectly > configured, but unaware of each other's actions. > > > I give it a kick manually, which of course involves entering an > > admin password... > > which is the necessity we're trying to avoid. > > ¹ There's another similar concern should you have more than one OS > thinking it's responsible for measuring and taking account of clock > drift. Whether this is going to concern people who are rebooting OSes > all the time is moot. > > Cheers, > David. >
Re: Time quandry when dual boot with WinXP Pro
On Fri 21 Oct 2016 at 18:47:43 (+0100), Joe wrote: > On Fri, 21 Oct 2016 09:58:42 -0500 > David Wrightwrote: > > > > . Neither OS was running when Civil Time changed to/from DST, > > . After the time changed, one OS has run, updating the Local Time to > > match Civil Time, . Another OS is just being booted up. > > > > What Local Time will eventually be displayed by this system? > > > DST may well be the answer. (I can't see how that answers anything, as I hadn't specified which way time changed, nor can I see why it would be an answer in either case.) My concern is that the second OS to boot might apply the time change in exactly the same manner as the first one did and should have done. So the system's Local Time would end up an hour fast (were this late Spring) or slow (were this late Fall) after the second OS applied its own time change. Or IOW what mechanism is there for one OS to find out whether another OS has altered the RTC by an hour any time recently?¹ > If I boot Linux on my Win8 laptop in the > summer, it knows the time perfectly well. If I now boot Win8, the clock > is an hour ahead. It does use a network time source but it does not > query the source on boot, or soon afterwards. Eventually it will do so, > but on a fixed schedule, so not for days, and there seems to be no way > to fix it. It's not just the first time after DST arrives, it's every > time. But isn't that just a configuration problem which I assume is unusual in that most people are not reporting that problem? What's more, you don't say whether your RTC is running UTC or some other time. Ignoring drift, a RTC running UTC never changes, so the hardware always knows the correct time. The Local Time displayed is just a matter of sensible configuration. My question, posed above, is *only* of concern where the RTC is running non-UTC, ie it gets fiddled with twice a year. At these two times, the RTC could be subject to incorrect alterations by erroneously configured OSes, or even multiple OSes perfectly configured, but unaware of each other's actions. > I give it a kick manually, which of course involves entering an admin > password... which is the necessity we're trying to avoid. ¹ There's another similar concern should you have more than one OS thinking it's responsible for measuring and taking account of clock drift. Whether this is going to concern people who are rebooting OSes all the time is moot. Cheers, David.
Re: Time quandry when dual boot with WinXP Pro
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 03:09:46PM -0500, Richard Owlett wrote: [...] If you want to get to the ground of things, on my system (yes, I'm on SysV init, for systemd you'll have to find out for yourself), the magic happens in /etc/init.d/hwclock.sh. This happens pretty early at boot. Now you'd have to find out when the relevant d-i setting takes place. Let us know :-) regards - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKe5QACgkQBcgs9XrR2kYAAACbBFdyBLP8NGPXg4OdQCB5Q/Ov dvMAn0Dr26NUzXBnAmENuIdByIuh69XB =QW2v -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
On 10/21/2016 2:24 PM, to...@tuxteam.de wrote: On Fri, Oct 21, 2016 at 09:11:07PM +0200, to...@tuxteam.de wrote: On Fri, Oct 21, 2016 at 09:21:17AM -0500, Richard Owlett wrote: [...] Relevant lines of preseed.cfg are ### Clock and time zone setup #d-i clock-setup/utc boolean false d-i clock-setup/utc boolean true d-i time/zone string US/Central d-i clock-setup/ntp boolean false To me this looks reasonable. At least the installer should have enough info to get by. Note that I'm not very fluent on the details, so I might be missing something. Here are the relevant pages [1] [2]. [1] & [2] bother me a little as they are labeled "(Obsolete Documentation)" They should imply possible search terms for additional research. My current motto - "If retirement isn't for learning, what use is it?" ;/ [3] also looks applicable. Will read all 3 after good night's sleep. Got a couple of other problems I should address today ;/ In a nutshell, it *should* work. But you lose the automatic DST change -- the OS expects then the HW clock to be "right" wrt local time. But -- who knows? Perhaps the hwclock is read *before* the d-i settings can be accounted for; perhaps the time will be right after installation *and* reboot? [1] https://www.debian.org/doc/manuals/system-administrator/ch-sysadmin-time.html [2] https://www.debian.org/doc/manuals/system-administrator/ch-sysadmin-time.html#s-multiboot-with [3] https://www.debian.org/doc/manuals/debian-handbook/sect.config-misc.en.html regards
Re: Time quandry when dual boot with WinXP Pro
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 09:11:07PM +0200, to...@tuxteam.de wrote: > On Fri, Oct 21, 2016 at 09:21:17AM -0500, Richard Owlett wrote: > > [...] > > > Relavant lines of preseed.cfg are > > > > ### Clock and time zone setup > > #d-i clock-setup/utc boolean false > > d-i clock-setup/utc boolean true > > d-i time/zone string US/Central > > d-i clock-setup/ntp boolean false > > To me this looks reasonable. At least the installer should have enough > info to get by. > > Note that I'm not very fluent on the details, so I might be missing > something. Here are the relevant pages [1] [2]. In a nutshell, it *should* work. But you lose the automatic DST change -- the OS expects then the HW clock to be "right" wrt local time. But -- who knows? Perhaps the hwclock is read *before* the d-i settings can be accounted for; perhaps the time will be right after installation *and* reboot? [1] https://www.debian.org/doc/manuals/system-administrator/ch-sysadmin-time.html [2] https://www.debian.org/doc/manuals/system-administrator/ch-sysadmin-time.html#s-multiboot-with regards - -- t -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKa18ACgkQBcgs9XrR2ka/wgCeNe9AumWLYJ3WBIG9eQuB1SLc fl4An0dEE+FYI91/RXelQQF1tVcXqzO1 =XANW -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 01:17:21PM -0500, Richard Owlett wrote: [...] > CONCLUSION > Can *NOT* blame Microsoft Windows for EVERYTHING ;/ My conclusion too. There's something else acting up. Linux should pick up the hw clock and *know* it's not in UTC, but in the noted timezone. Hmmm. regards - -- t -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKaMwACgkQBcgs9XrR2kYfdACfewFmXgPBX2BQKDZ5nVvoWTCr GuQAn3eAN+ZDtL6Sv8Y30vHRbaXx/5L+ =UMEO -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 09:21:17AM -0500, Richard Owlett wrote: [...] > Relavant lines of preseed.cfg are > > ### Clock and time zone setup > #d-i clock-setup/utc boolean false > d-i clock-setup/utc boolean true > d-i time/zone string US/Central > d-i clock-setup/ntp boolean false To me this looks reasonable. At least the installer should have enough info to get by. Note that I'm not very fluent on the details, so I might be missing something. regards - -- t -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKaEsACgkQBcgs9XrR2kYisACePF8aAPUqrKh8bauMcYo5knvj wN4An2XW5A/HGXxUuCP2q5/R4XpqZ3F+ =a9Gh -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
On 10/21/2016 11:46 AM, Doug wrote: On 10/21/2016 10:21 AM, Richard Owlett wrote: On 10/21/2016 8:32 AM, to...@tuxteam.de wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot environment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. Uh, oh. Microsoft and time handling. This won't end well :-/ *ROFL* *KEY* text text from original post was not quoted. I have discovered on my WinXP machine that: 1. WinXP _displays_ the correct time. "Date and Time Properties" - Time Zone set to (GMT-06:00)Central Time(US) Automatically adjust clock for daylight saving changes 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false Yes, It's Windows' fault. Unfortunately, I don't remember the details, but the cure is in the Registry. If you google the problem, somewhere along the way, you will find the Registry hack that fixes the problem. *Begin test sequence* power off power on start Debian - time displayed 08:00 AM power off power on start WinXP Pro SP3 - time displayed 01:00 PM "Shut Down Windows" choosing "Restart" menu option Chose Debian from Grub menu - time displayed 08:00 AM shut down with restart option Run Debian from Live DVD - time displayed 13:12 Shut down with power off power on Run Debian from Live DVD - time displayed 13:12 *EOT* CONCLUSION Can *NOT* blame Microsoft Windows for EVERYTHING ;/ --doug This observation alone suggests strongly that this installation "thinks" it should use the UTC (or any equivalent) time zone to fudge back its way from the hardware clock to the UTC. What is the value of d-i time/zone? Relevant lines of preseed.cfg are ### Clock and time zone setup #d-i clock-setup/utc boolean false d-i clock-setup/utc boolean true d-i time/zone string US/Central d-i clock-setup/ntp boolean false regards - -- tomás
Re: Time quandry when dual boot with WinXP Pro
On Fri, 21 Oct 2016 09:58:42 -0500 David Wrightwrote: > > . Neither OS was running when Civil Time changed to/from DST, > . After the time changed, one OS has run, updating the Local Time to > match Civil Time, . Another OS is just being booted up. > > What Local Time will eventually be displayed by this system? > DST may well be the answer. If I boot Linux on my Win8 laptop in the summer, it knows the time perfectly well. If I now boot Win8, the clock is an hour ahead. It does use a network time source but it does not query the source on boot, or soon afterwards. Eventually it will do so, but on a fixed schedule, so not for days, and there seems to be no way to fix it. It's not just the first time after DST arrives, it's every time. I give it a kick manually, which of course involves entering an admin password... -- Joe
Re: Time quandry when dual boot with WinXP Pro
On 10/21/2016 10:21 AM, Richard Owlett wrote: On 10/21/2016 8:32 AM, to...@tuxteam.de wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot enviroment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. Uh, oh. Microsoft and time handling. This won't end well :-/ *ROFL* 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false Yes, It's Windows' fault. Unfortunately, I don't remember the details, but the cure is in the Registry. If you google the problem, somewhere along the way, you will find the Registry hack that fixes the problem. --doug This observation alone suggests strongly that this installation "thinks" it should use the UTC (or any equivalent) time zone to fudge back its way from the hardware clock to the UTC. What is the value of d-i time/zone? Relavant lines of preseed.cfg are ### Clock and time zone setup #d-i clock-setup/utc boolean false d-i clock-setup/utc boolean true d-i time/zone string US/Central d-i clock-setup/ntp boolean false regards - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKGNkACgkQBcgs9XrR2kbE3wCfazy79csBl1oVWD0IZp5D2nGZ bUMAnivHeC+RC3CfgBy7LzoAD16wCZaF =wguH -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
On Fri 21 Oct 2016 at 14:28:26 (+0100), Darac Marjal wrote: > On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: > >I'm creating a preseed.cfg file for installing Debian 8.6 in a > >dual-boot enviroment with some version of MS Windows. There are > >two distinct use cases: > > [snipped] > > If you're not using NTP to provide your time, then, at boot, the > operating system will query the "hardware clock" to see what time it > is. As the hardware clock can drift, operating systems will also > set the hardware clock to match the "system clock" at shutdown time > (the system clock is the time that the operating system is using). > > The problem comes that there is no way for the hardware clock > (HWClock) to report what timezone it was set to. There are basically > two options here: > > 1. The HWClock is set to "Local Time". In this case, the operating > system sees "12:23" as being "12:23 GMT" or "12:23 CST" or whatever > and attempts no translation of the clock. > > 2. The HWClock is set to "Universal Time" (which is a > non-geographical datum time zone, with no daylight changes). In this > case, the operating system sees "12:23" as ONLY being "12:23 UTC" > and translates that into the local time zone by adding or > subtracting hours appropriately. > > If you only have one operating system on your machine, either of > these methods is fine. If you have TWO (or more) operating systems, > though, then they SHOULD agree on what the time in the HWClock > represents. If Windows thinks it's local time, but Debian thinks > it's UTC, then you'll see five-hour shifts each time you boot. > > You've already found the setting in Debian, I see, so you probably > want to check it tallies with what Windows is using. For that, look > at the Registry Key > HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal. > If this is 1, then the HWClock is using UTC; if it is 0, then the > HWClock is set to local time. So what happens with the scenario: . No NTP connection, . Hardware clock running on Local Time, . Two or more OSes that know these two facts. . Neither OS was running when Civil Time changed to/from DST, . After the time changed, one OS has run, updating the Local Time to match Civil Time, . Another OS is just being booted up. What Local Time will eventually be displayed by this system? Cheers, David.
Re: Time quandry when dual boot with WinXP Pro
On 10/21/2016 8:28 AM, Darac Marjal wrote: On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot enviroment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. I have discovered on my WinXP machine that: 1. WinXP _displays_ the correct time. "Date and Time Properties" - Time Zone set to (GMT-06:00)Central Time(US) Automatically adjust clock for daylight saving changes 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false is used in the preseed.cfg file. I'm confused. If you're not using NTP to provide your time, Mine are not. His I don't know. then, at boot, the operating system will query the "hardware clock" to see what time it is. As the hardware clock can drift, operating systems will also set the hardware clock to match the "system clock" at shutdown time (the system clock is the time that the operating system is using). The problem comes that there is no way for the hardware clock (HWClock) to report what timezone it was set to. There are basically two options here: 1. The HWClock is set to "Local Time". In this case, the operating system sees "12:23" as being "12:23 GMT" or "12:23 CST" or whatever and attempts no translation of the clock. 2. The HWClock is set to "Universal Time" (which is a non-geographical datum time zone, with no daylight changes). In this case, the operating system sees "12:23" as ONLY being "12:23 UTC" and translates that into the local time zone by adding or subtracting hours appropriately. If you only have one operating system on your machine, either of these methods is fine. If you have TWO (or more) operating systems, though, then they SHOULD agree on what the time in the HWClock represents. If Windows thinks it's local time, but Debian thinks it's UTC, then you'll see five-hour shifts each time you boot. You've already found the setting in Debian, I see, so you probably want to check it tallies with what Windows is using. For that, look at the Registry Key HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal. If this is 1, then the HWClock is using UTC; if it is 0, then the HWClock is set to local time. On my system, regedit does not display that key. Instead it has HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\ActiveTimeBias HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\Bias HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\StandardBias with respective values of (300), (360), and (0) Hopefully that helps. It clarifies what's happening. For my pesonal machines it doesn't make much difference, will likely just go to UTC for both clock and displayed time. For my friend's machines there are non-technical, as well as technical, issues involved.
Re: Time quandry when dual boot with WinXP Pro
On 10/21/2016 8:32 AM, to...@tuxteam.de wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot enviroment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. Uh, oh. Microsoft and time handling. This won't end well :-/ *ROFL* 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false This observation alone suggests strongly that this installation "thinks" it should use the UTC (or any equivalent) time zone to fudge back its way from the hardware clock to the UTC. What is the value of d-i time/zone? Relavant lines of preseed.cfg are ### Clock and time zone setup #d-i clock-setup/utc boolean false d-i clock-setup/utc boolean true d-i time/zone string US/Central d-i clock-setup/ntp boolean false regards - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKGNkACgkQBcgs9XrR2kbE3wCfazy79csBl1oVWD0IZp5D2nGZ bUMAnivHeC+RC3CfgBy7LzoAD16wCZaF =wguH -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: > I'm creating a preseed.cfg file for installing Debian 8.6 in a > dual-boot enviroment with some version of MS Windows. There are two > distinct use cases: >1. Two of my machines with WinXP Pro SP3 >2. A remote (~1000 miles]friend with several machines - some with > WinXP, others with > Windows 10 or later. Uh, oh. Microsoft and time handling. This won't end well :-/ [...] >3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom > preseed.cfg > _displays_ a time 5 hours earlier. > The _display_ is independent of whether >d-i clock-setup/utc boolean true >*OR* >d-i clock-setup/utc boolean false This observation alone suggests strongly that this installation "thinks" it should use the UTC (or any equivalent) time zone to fudge back its way from the hardware clock to the UTC. What is the value of d-i time/zone? regards - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlgKGNkACgkQBcgs9XrR2kbE3wCfazy79csBl1oVWD0IZp5D2nGZ bUMAnivHeC+RC3CfgBy7LzoAD16wCZaF =wguH -END PGP SIGNATURE-
Re: Time quandry when dual boot with WinXP Pro
On Fri, Oct 21, 2016 at 08:09:38AM -0500, Richard Owlett wrote: I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot enviroment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. I have discovered on my WinXP machine that: 1. WinXP _displays_ the correct time. "Date and Time Properties" - Time Zone set to (GMT-06:00)Central Time(US) Automatically adjust clock for daylight saving changes 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false is used in the preseed.cfg file. I'm confused. If you're not using NTP to provide your time, then, at boot, the operating system will query the "hardware clock" to see what time it is. As the hardware clock can drift, operating systems will also set the hardware clock to match the "system clock" at shutdown time (the system clock is the time that the operating system is using). The problem comes that there is no way for the hardware clock (HWClock) to report what timezone it was set to. There are basically two options here: 1. The HWClock is set to "Local Time". In this case, the operating system sees "12:23" as being "12:23 GMT" or "12:23 CST" or whatever and attempts no translation of the clock. 2. The HWClock is set to "Universal Time" (which is a non-geographical datum time zone, with no daylight changes). In this case, the operating system sees "12:23" as ONLY being "12:23 UTC" and translates that into the local time zone by adding or subtracting hours appropriately. If you only have one operating system on your machine, either of these methods is fine. If you have TWO (or more) operating systems, though, then they SHOULD agree on what the time in the HWClock represents. If Windows thinks it's local time, but Debian thinks it's UTC, then you'll see five-hour shifts each time you boot. You've already found the setting in Debian, I see, so you probably want to check it tallies with what Windows is using. For that, look at the Registry Key HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal. If this is 1, then the HWClock is using UTC; if it is 0, then the HWClock is set to local time. Hopefully that helps. -- For more information, please reread.
Time quandry when dual boot with WinXP Pro
I'm creating a preseed.cfg file for installing Debian 8.6 in a dual-boot enviroment with some version of MS Windows. There are two distinct use cases: 1. Two of my machines with WinXP Pro SP3 2. A remote (~1000 miles]friend with several machines - some with WinXP, others with Windows 10 or later. I have discovered on my WinXP machine that: 1. WinXP _displays_ the correct time. "Date and Time Properties" - Time Zone set to (GMT-06:00)Central Time(US) Automatically adjust clock for daylight saving changes 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom preseed.cfg _displays_ a time 5 hours earlier. The _display_ is independent of whether d-i clock-setup/utc boolean true *OR* d-i clock-setup/utc boolean false is used in the preseed.cfg file. I'm confused.