similar to: domU time slipping behind dom0

Hello ! Just a quick question about time synchronization between xen dom0 and domUs... We''re running Xen 3.1 64-bit, with 32 and 64 bits linux guests. It''s up since 89 days and the domU''s time is around 5 minutes behind the dom0, which is updated via ntpdate... Any idea why it doesn''t sync the guests even that /proc/sys/xen/independent_wallclock is 0 ?

If independent_wallclock is set to 0, then that means running ''date'' in the domU should provide exactly the same answer as running ''date'' on dom0, right? But this isn''t happening for us. The domU''s are all running minutes behind the dom0 - in one case 16 minutes behind! dom0$ date Tue Jun 27 14:23:01 BST 2006 domU-a$ date Tue Jun 27

I recently put together a new machine w/ a SuperMicro H8SCM and an AMD Opteron 4228 HE... I've having an issue where the clock on the machine skips around... The wierd part is that it's very sudden when it happens... ntp sometimes brings it back, but it can't when the clock gets too far ahread (1000 seconds), ntp dies... In order to catch it happening, I ran a sleep 60 loop

I think it''s perfect the way it is. Run NTP in dom0, all the domU''s then have synchronized time. I can still set timezones on all of these boxes independantly. Timezone has nothing to do with NTP synchronization. Tim:> > yeah, i''m already doing that, I was just saying, it *seemed* > like they were getting their time from domain0, and weren''t >

This must be documented somewhare but I checked the Xen 3.0 manual and the word "clock" doesn''t even exist in it. I checked the FAQ as well. I am running Xen 3.0.1 and an AMD64 CPU. I found that DOMUs time clock drifts ahead. I installed ntpdate and it reports to change the time but it does not. David _______________________________________________ Xen-users mailing list

Hi all, I''m experiencing problems with time: after I sync time both into dom0 and dom1 with public ntp servers, times are not the same. Do you have the same problem? Thanks Marco _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users

Hi everyone, I have the problem with Xen domU's and timekeeping in dom0. Time in dom0 was incorrect by 5 hours due to wrong timezone assumed. Fixed it by ntpdate ntp.nist.gov. The time on a dom0 was changed. I didn't append xen.independent_wallclock=1 to sysctl.conf thus the time in all domU's was also changed. But THEY DIDN'T "KNOW" THAT! The 'date' output

Hi all, can anybody please explain me what changes if i set independent_wallclock to 1 in dom0. I know that setting it to 1 in domU means that the domU will have his clock running independently from dom0 but I don''t understand what does it means setting it to 1 in dom0. Regards -- Dario Fiumicello _______________________________________________ Xen-users mailing list

Hi all, where can I set the date in domU. ''ntpdate -u ...'' works but dosn''t set the date. date MMDDhhmm has also no effect. What can I do? -- cu Roland Kruggel  mailto: rk-liste@gmx.de System: Intel 3.2Ghz, Debian etch, 2.6.15, KDE 3.4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com

Hello, I''m hiring a XEN virtual machine running Ubuntu at a hosting company. My XEN virtual machine is hosted on a server which has some other VM''s running on it. They all use ubuntu or debian. After a crash sometime last week, the systemclock of my VM is off by an hour (it says 19:49, although it''s 18:49 here now). The other VM''s don''t have

While in the upstream kernel I''m unable to find any use of XENPF_settime (and the DOM0_SETTIME alias of it) at all, in the 2.6.18 tree (and the forward ports of it) the function gets used only when ntp_synced() returns true (and - that''s minor - when independent_wallclock is not set). It would however seem to me that this doesn''t cover the case where the host clock gets

Hi list, one and hopefully last strange thing I figured out ist the systime of my guests. Dom0 uses ntp for time syncronisation. I set the time on my guests manually but after reboot any machine (Windows server, XP, Freebsd, even PV Machines like ubuntu) all run local time - 2 hours. /proc/sys/xen/independent_wallclock is set to 0 so actually the time should be set by dom0...(?) Any

Hi everybody! I know this is an ultraknown issue, but in my case i think it is going beyond. As you may guess my domUs clocks go faster or slower They come with the same OS (Centos 5 2.6.18-92.1.18.el5 ) but each of them have a different clock speed. Why? Dom0 does not syncronize domUs : So i watched out looking for any solution.... First attempt: /proc/sys/xen/independent_wallclock = 0

This is really stupid question. But referring to: http://lists.centos.org/pipermail/centos/2009-October/083791.html I don't see any line related to ntpd in my /var/log/messages . Do I need to turn-on ntpd for timekeeping on VMs? Some people say not to use ntpd on VMs for timekeeping or is it ntpdate cron job? Can someone please elaborate on this? Thanks, Jonathan. -------------- next part

Hey, 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. Any tip would be appricated. Thanks, -- ++ytti

Hello. On kernel from linux-image-2.6.18-6-xen-686, there is /proc/sys/xen/independent_wallclock sysctl that may be used to decoupte domU clock from domO clock. This is needed to run ntp in domU. On kernel from linux-image-2.6.26-1-xen-686, there is no such ioctl. Is that a bug or a feature? Is it possible to decoupte domU clock from domO clock when domU is running on

Package: xen Severity: important Version: 4.0.1-1 The Xen documentation and Xen Debian wiki describes using independent_wallclock to sync domU clocks against the dom0 clock http://docs.vmd.citrix.com/XenServer/4.0.1/guest/ch04s06.html http://wiki.debian.org/Xen#Possible_problems_and_bugs-1 This sysctl appears to have gone away with squeeze, but the documentation is not updated Time drift is

Hi all, finally I have managed to upgrade to Xen 4.0 (actually it reports Xen 4.1-unstable) and Debian''s Linux kernel 2.6.32-4-xen-amd64. Now I am wondering what happend to independent_wallclock. There is no more /sys/xen and sysctl complains error: "xen.independent_wallclock" is an unknown key Does anybody know more about this? Thanks + best regards, Stephan

Hi all, finally I have managed to upgrade to Xen 4.0 (actually it reports Xen 4.1-unstable) and Debian''s Linux kernel 2.6.32-4-xen-amd64. Now I am wondering what happend to independent_wallclock. There is no more /sys/xen and sysctl complains error: "xen.independent_wallclock" is an unknown key Does anybody know more about this? Thanks + best regards, Stephan

Hello, I know, often asked, often discussed .. No recommendation from Citrix. What is the better solution? 1) use ntp in the XEN host and synchronize the guests with the clock running on the control domain (independent_wallclock=0, what the default is) 2) or use ntp in host and guest (and independent_wallclock=1) I ask, because the XEN host (bare metal) has a more stable clock and if the ntp