Fedora directory users - Jul 2007 - replica multi-master, clock skew and /etc/ntp.conf

Hi there,
i am setupping replica multi-master, and things seems to go ahead; for other 
newbies like me, i suggest to have file hosts and named daemon setupped very 
carefully regarding reverse resolution of the other master in replica 
agreement.
The only trouble, now, is clock skew: i am developing on a server with vmware 
server; 2 master are 2 virtual centos on vmware server.
I am trying to get their clock synced each other or, at least, with dom0 
server, with no success.
Someone there has a very bare and simple /etc/ntp.conf to get 2 master servers 
time synced?
Any help will be very appreciated
	Maurizio

On Mon July 2 2007 11:56, Maurizio Marini wrote:
> Someone there has a very bare and simple /etc/ntp.conf to get 2 master
> servers time synced?
The distro configuration is ok, it is necessary to wait half an hour after 
ntpd restart on server, before trying to sync time from clients.
	m.

VM-ware somtimes has annoying clock issues.

If you are using a VMware supported Kernel on a VMware supported OS
you should be able to ''install vmware tools'' - run the RPM be
ok.

I am on Fedora Core 5. This is what I have to do.

My VMWare machines have I have found that using VMWare server with the
stock FC5 kernel works and vmware 1.0.1 works ''OK'' as long as:

-You install VMware tools on the guest os
-You turn on the real time clock in the configuration of vmware tools
-You change clock=PIT in the kernel boot
-You only use one processor for the system.

Your milage on this may vary depending on what kernel / vmware
combination you are using.

With two processor emulation I found the clock totally irradic, and
the host system was telling me about soft lockups. I found that for
most things one processor emulation works well enough.

Here is what I do:
install kernel-source/kernel-devel
In vmware click ''install vmware tools''
This creats a pseudo CD device that you have to mount ( I do not remember how)
In the psuedo cd-rom device there are two files
VMware-Tools-1.0.1-(version).rpm and the tar
I RPM install the tar
download vmware-any-any-update105.tar.gz
vmware-tools-any-update1.tar.gz
tar -xf vmware-tools-any-update1.tar.gz
tar -xf vmware-any-any-update105.tar.gz
cp vmware-tools-any-update/runme.pl
vmware-any-any-update/runme.pl
cd vmware-any-any-update
perl runme.pl
Set clock=pit in kernel config
Reboot

Still, I find if the system is very busy I have found the clock
jumping a minute and then jumping back. I still run ntp sometimes
against suggestion of vmware. Then again I am not on a supported OS.


On 7/2/07, Maurizio Marini <maumar.marini@cost.it>
wrote:
> Hi there,
> i am setupping replica multi-master, and things seems to go ahead; for
other
> newbies like me, i suggest to have file hosts and named daemon setupped
very
> carefully regarding reverse resolution of the other master in replica
> agreement.
> The only trouble, now, is clock skew: i am developing on a server with
vmware
> server; 2 master are 2 virtual centos on vmware server.
> I am trying to get their clock synced each other or, at least, with dom0
> server, with no success.
> Someone there has a very bare and simple /etc/ntp.conf to get 2 master
servers
> time synced?
> Any help will be very appreciated
>        Maurizio
>
> --
> Fedora-directory-users mailing list
> Fedora-directory-users@redhat.com
> https://www.redhat.com/mailman/listinfo/fedora-directory-users
>

VMWare suggests you do NOT run NTP on the guest OS, only the master. You do
not need your own ntp server to run ntp.

If you go to the VMWare site and forums there are many discussions on clock
scew.

The way VMware virtualzes the system plays total havoc on the clocks. They
might count slow or really fast, or jump forward and backwards.

Also your terminology is confusing ''dom0'' is a XEN thing
'' guest os'' is a
vmware thing. It is hard to tell which product you are using.

If you are using VMware and the clock is slow or jumping around refer to my
first post. If you are XEN I can not help much.



On 7/2/07, Maurizio Marini <maurizio.marini@cost.it>
wrote:
>
> On Mon July 2 2007 11:56, Maurizio Marini wrote:
> > Someone there has a very bare and simple /etc/ntp.conf to get 2 master
> > servers time synced?
> The distro configuration is ok, it is necessary to wait half an hour after
> ntpd restart on server, before trying to sync time from clients.
>         m.
>
> --
> Fedora-directory-users mailing list
> Fedora-directory-users@redhat.com
> https://www.redhat.com/mailman/listinfo/fedora-directory-users
>

On Tue July 3 2007 16:42, Eddie C wrote:
> VMWare suggests you do NOT run NTP on the guest OS, only the master. You do
> not need your own ntp server to run ntp.
>
> If you go to the VMWare site and forums there are many discussions on clock
> scew.
>
> The way VMware virtualzes the system plays total havoc on the clocks. They
> might count slow or really fast, or jump forward and backwards.
Yes, i saw :(
>
> Also your terminology is confusing ''dom0'' is a XEN thing
'' guest os'' is a
> vmware thing. It is hard to tell which product you are using.
Sorry, i used dom0 instead of guest OS :)
your help was very apreciated and i instaled vmware-tools after reading your 
post :)
Many thnx :)
	Maurizio