Re: [gentoo-user] hwclock <--> sysclock and the ntp-client

Michael Mol <mikemol@×××××.com> [12-02-06 19:56]:
> On Mon, Feb 6, 2012 at 1:39 PM,  <meino.cramer@×××.de> wrote:
> > Michael Mol <mikemol@×××××.com> [12-02-06 19:20]:
> >> On Mon, Feb 6, 2012 at 12:51 PM,  <meino.cramer@×××.de> wrote:
> >> > Hi,
> >> >
> >> > to get the correct system time I use ntp-client in the boot process.
> >> > Furthermore in /etc/conf.d/hwclock I set:
> >> >
> >> >    # Set CLOCK to "UTC" if your Hardware Clock is set to UTC (also known as
> >> >    # Greenwich Mean Time).  If that clock is set to the local time, then
> >> >    # set CLOCK to "local".  Note that if you dual boot with Windows, then
> >> >    # you should set it to "local".
> >> >    clock="UTC"
> >> >
> >> >    # If you want to set the Hardware Clock to the current System Time
> >> >    # (software clock) during shutdown, then say "YES" here.
> >> >    # You normally don't need to do this if you run a ntp daemon.
> >> >    clock_systohc="YES"
> >> >
> >> >    # If you want to set the system time to the current hardware clock
> >> >    # during bootup, then say "YES" here. You do not need this if you are
> >> >    # running a modern kernel with CONFIG_RTC_HCTOSYS set to y.
> >> >    # Also, be aware that if you set this to "NO", the system time will
> >> >    # never be saved to the hardware clock unless you set
> >> >    # clock_systohc="YES" above.
> >> >    clock_hctosys="NO"
> >> >
> >> >    # If you wish to pass any other arguments to hwclock during bootup,
> >> >    # you may do so here. Alpha users may wish to use --arc or --srm here.
> >> >    clock_args=""
> >> >
> >> > In the kernel config file I had set:
> >> >
> >> >    CONFIG_RTC_HCTOSYS=y
> >> >    CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
> >> >
> >> > I would exspect that after a reboot of the system which system time is
> >> > correctly set via ntp-client that the hwclock and system time only
> >> > differ in a small amount of time.
> >> >
> >> > But:
> >> > solfire:/home/mccramer>hwclock
> >> > Mon Feb  6 19:05:11 2012  -0.172569 seconds
> >> > solfire:/home/mccramer>date
> >> > Mon Feb  6 18:49:37 CET 2012
> >> > solfire:/home/mccramer>
> >>
> >> I don't know the CET tz, but I can see that the minutes don't match
> >> up. I assume you rand the two commands within seconds of each other.
> >> Is this true immediately after bootup, or does it take a while to get
> >> that far off? It could be that your hardware clock is drifting, and
> >> the system won't reset it until it goes to shutdown.
> >>
> >> --
> >> :wq
> >>
> >
> > Hi Michael,
> > thank you for your reply.
> > I set the configuration as mentioned above and booted twice with about
> > five minutes wait.
> > The commands were executed within seconds, yes.
> > All hardware clocks drifts, but this is not the problem.
> > The problem is that the hardware clock is not set to the system time
> > in contradiction to what I think the comments in the config are
> > saying.
> >
> > How can I fix that?
>
> I don't really know. Are you sure that rtc0 corresponds to your
> hardware clock device? Does setting "clock_hctosys" to YES have any
> effect?
>
> Is this in some kind of virtual-machine or hypervised environment
> where something may be blocking the OS from setting the hardware
> clock?
>
> --
> :wq
>

It is set

lrwxrwxrwx 1 root root       4 2012-02-07 00:52 /dev/rtc -> rtc0
crwxrwx--- 1 root audio 254, 0 2012-02-07 00:52 /dev/rtc0

and it is the only device of its kind. 

As I wrote I am using ntp_client for setting my system time while
booting up.
So reagrdless wheter I am setting clock_hctosys I am alway getting 
the correct system time later in the bootprocess via ntp.