similar to: timekeeping on VM - ntpd running

Hello, I was thinking of creating a wiki page about Xen clocksources and timekeeping.. including dom0, PV guests and HVM guests. Dan and Jeremy: You guys might have some ideas for this page.. please let me know your thoughts :) Subjects to cover: - Xen hypervisor clocksources (hpet, acpi_pm, pit) - Xen dom0 clocksource, ntpd, etc - Xen PV guest clocksources, independent_wallclock, ntpd,

Stan, Thanks for the reply. In our case we have actually already done most of the work you suggested to no avail. We had rebuilt two new ntp servers that sync against two stratum 1 sources, and all our nfs clients, regardless of using dovecot, sync to those two machines. You bring up the difference between bare metal and hypervisor, and we are running these machines on vmware 4.0. All the

A shell script is deployed to synchronize time, the script is invoked hourly by crontab, and its content is as follows: #!/bin/bash service ntpd stop ntpdate 192.168.0.191 #it's a valid ntpd server in LAN service ntpd start chkconfig ntpd on Inspected the Linux log(Centos6.4 /var/log/messages), found the following fragment: Jan 7 14:00:01 host1 ntpd[32101]: ntpd exiting on signal 15 Jan 7

Hi guys, Thanks for your reply. I originally used the following command to synchronize time: ntpdate 192.168.0.191 but got the error: ntpdate[16715]: the NTP socket is in use, exiting So i used the way of stopping ntpd service. Now I have known that using command "ntpdate -u 192.168.0.191" can solve the above error, and also know using ntpdate command is an improper way, i.e. should use

Hello, all. I would like to use ntpd for time sync not rdate or ntpdate. but after installation the ntpd, I found that listened at all interfaces like below. udp 0 0 192.168.111.2:123 0.0.0.0:* 11528/ntpd udp 0 0 xxx.xxx.62.20:123 0.0.0.0:* 11528/ntpd udp 0 0

Howdy, I am having time-drift issues on my CentOS VM. I had referred to following documentation: http://wiki.centos.org/TipsAndTricks/VMWare_Server , however it didn't help. I used kickstart for creating this VM and I am listing important steps in ref to timekeeping issue. Any comments or suggestion would be appreciated. - CS. ------------------- # For EL5 virtual machines, Append the

Is there a package to do this? Normally the hardware clock is set during shutdown if one is running ntpd. But if a long-running server shuts down unexpectedly, this isn't done, and the hardware clock might be off by a lot when it comes back up. So setting it periodically from a cron job could be useful. What do others do? Adding a one liner to /etc/cron.daily that invokes

Scenario: server PC abruptly switched off due to power cable problems (an UPS cannot solve this issue), so during shutdown Linux was not able to resinchronize the system clock. After a few hours the server come back on, Linux booted and the services (ntpd, dovecot and many others) started But the system clock was 45 minutes ahead, so: Jan 19 11:13:39 gw ntpd[2112]: synchronized to LOCAL(0),

Hello, in system-config-date i have checkbox synchronize date before service startup. Which config switch,file does it affect? I want to turn it on on my CentOS machine without xauth , just editing config files , i was hoping it could be in /etc/sysconfig/ntpd but no. Thanks in advance! D. -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hi All, I am using vms on gogrid and rackspace completely. I am decent but still learning puppet. The biggest problem with vms, especially where I cant control the Host is ntp time and date sync to be good. Here is my config to sync ntp. Please dont tailor my code just help me fix the problem. This code works 99% of the servers its on except for 2 centos 5 machines. class base { class {

I've seen situations where people have put ntpdate in a cronjob to get around issues with big time jumps at boot or dodgy clocks under virtualization. There are much better solutions to this problem, so let us know if this is the case for you. K

Hi there, I've been a happy djbdns+tinydns user for many, many years. I want to keep using it, so answers of the form "bletch! Use ISC BIND the way BSD intended" will be ignored :-) Having said that, one annoying consequence of my transition some time ago to using ntpd, rather than just setting the clock once-off with ntpdate as I used to, is that the /etc/rc.d mechanism starts

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 ?

The time appears to be perfect inside dom0, however all the domU''s tend to have a slightly faster date which gets further out of sync every day. I''m currently using Xen 3.0.3 with Gentoo Linux, under 3.0.2 I had no problems with domU clocks. Are there any known issues which could cause this? I''d strongly prefer not to run ntpd in every domU, having all domU clocks in

Hello *, strange happening yesterday. See this logfile lines: Sep 10 20:45:52 seymour ntpd[9104]: synchronized to 192.53.103.108, stratum 1 Sep 10 20:58:07 seymour ntpd[9104]: synchronized to 134.34.3.18, stratum 1 Sep 10 21:21:02 seymour dovecot: dovecot: Fatal: Time just moved backwards by 434 seconds. [ ... ] Sep 10 21:26:36 seymour ntpd[9104]: no servers reachable Sep 10 21:42:56 seymour

Hi, I have a dual core athlon server and it is gaining 1 day every 2 days w/o time sync. Even with ntpd running, the time is not under control. I must put a very frequent cronjob of 'ntpdate' to keep the time under control. This creates big problems since winbind eventually stops working so my users can't access their data. Any ideas? -- Ugo -> Please don't send a copy of

People at vmware have provided patches for RHEL 5 that aim to fix timekeeping issues in vmware guests. https://bugzilla.redhat.com/show_bug.cgi?id=463573 Description of problem (excerpt) : "In a virtual environment, timekeeping for RHEL 64 bit kernels can be problematic, since time is kept by counting timer interrupts for this kernel. The problem arises when the VM is descheduled for some

On 03/03/16 09:18, Patrick Masotta wrote: >>>> How so? > > it says they cannot emulate the timer interrupt very well; > that's what I understood... If it's the VMware document I'm thinking of (titled "Timekeeping in VMware Virtual Machines"), then the issue is that emulating the timer interrupt can cause a heavy load on the host if the guest timer is

OK, So what you people say is : 1. Run "ntpdate" during startup only once 2. After that, keep time with ntpd Right ? Regards, spyros ---- "I merely function as a channel that filters music through the chaos of noise" - Vangelis

In 780427f0e11 (Indicate that clock was set in the pvclock gtod notifier), logic was added to pass a CLOCK_WAS_SET notification to the pvclock notifier chain. While that patch added a action flag returned from accumulate_nsecs_to_secs(), it only uses the returned value in one location, and not in the logarithmic accumulation. This means if a leap second triggered during the logarithmic