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Re: [Xen-devel] domU clock over 23s off


On Feb 26, Keir Fraser wrote:

> >I have rather new installation of xen, dom0 is running ntpd and is
> >perfectly in time. All domU's are ~23s in future. Running ntpd on
> >the domU's seem to have no effect, /proc/sys/xen/independent_wallclock
> >appears to have no effect. I'm running xen-unstable and 2.6.16-rc4
> >in AMD64 box.
> Booting the domU's with 'independent_wallclock' as a command-line 
> parameter, and then running a standard vendor ntp init script (usually 
> ntpdate followed by starting ntpd) certainly *should* have fixed the 
> domU time problem.

I run into the same problem (ntp not working), so I set independent_wallclock
and ntp un domU can set the system time.  thanks for the hint!

BUT!!!  with independent_wallclock I have a new problem:
now the hw clock can't be read anymore

        root@rhel4 # /sbin/hwclock --debug
        hwclock from util-linux-2.12a
        hwclock: Open of /dev/rtc failed, errno=19: No such device.
        No usable clock interface found.
        Cannot access the Hardware Clock via any known method.

this causes system to start up with system time "1 Jan 1970"

        # grep 1970 /var/log/boot.log
        Jan  1 01:00:10 os2-rhel4 date: Do Jan  1 01:00:10 CET 1970 
        Jan  1 01:00:10 os2-rhel4 rc.sysinit: Stelle Uhr  (localtime) auf: Do 
Jan  1 01:00:10 CET 1970 succeeded 

and in /var/log/messages:

        Jul 11 17:26:00 os2-rhel4 exiting on signal 15
        Jan  1 01:00:17 os2-rhel4 syslogd 1.4.1: restart.
        Jan  1 01:00:26 os2-rhel4 xinetd[1307]: xinetd Version 2.3.13 started 
with libwrap loadavg options compiled in.
        Jan  1 01:00:26 os2-rhel4 xinetd[1307]: Started working: 2 available 
        Jul 11 17:31:56 os2-rhel4 ntpdate[1321]: step time server 
offset 1152692789.758448 sec
        Jul 11 17:31:56 os2-rhel4 ntpd:  succeeded
        Jul 11 17:31:56 os2-rhel4 ntpd: Starten von ntpd succeeded

not only there are many bogus time stamps in log files, it also causes
a file system check at every startup because the fs was mounted last time
"so long ago":

        # /sbin/tune2fs -l /dev/hda1 |grep 1970  
        Last mount time:          Thu Jan  1 01:00:21 1970
        Last checked:             Thu Jan  1 01:01:36 1970

my current setup is:  AMD64 dual-core dual-opteron 

        Xen version 3.0.1 (xenod@xxxxxxxxxxxx) (gcc version 3.4.4 20050721 (Red 
Hat 3.4.4-2)) Tue Jan 31 15:26:55 GMT 2006
        Latest ChangeSet: Tue Jan 31 11:04:12 2006 +0100 8738:eff96462fde8

dom0 and domU kernel:
        Linux version (xenod@xxxxxxxxxxxxxxxxxxxx) (gcc version 
3.4.4 20050721 (Red Hat 3.4.4-2)) #1 SMP Tue Jan 31 15:36:43 GMT 2006

will an update to a more recent XEN version fix these problems ?

if yes, what do I have to replace/update ? 
only domU kernel? or dom0+domU ? 
only hypervisor? or just everything ?

thanks for every help!!

Harald Koenig
"I hope to die                                      ___       _____
before I *have* to use Microsoft Word.",           0--,|    /OOOOOOO\
Donald E. Knuth, 02-Oct-2001 in Tuebingen.        <_/  /  /OOOOOOOOOOO\
                                                    \  \/OOOOOOOOOOOOOOO\
                                                      \ OOOOOOOOOOOOOOOOO|//
Harald Koenig                                          \/\/\/\/\/\/\/\/\/
science+computing ag                                    //  /     \\  \
koenig@xxxxxxxxxxxxxxxxxxxx                            ^^^^^       ^^^^^

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