open-vm-tools-devel

Time keeps on slippin slippin slippin slippin... into the future...

[John L. <jo...@jo...>]

Just like the song says, the time on my SLES 11 server "keeps on
slippin slippin slippin... into the future..."

The vmware-guestd are started at boot and are running.

The following modules are loaded:

# lsmod |grep vm
vmsync                  5440  0
vmmemctl               10188  0
vmblock                15124  1

Yet clocks keeps skewing forward at a rapid pace.

This VM is used for monitoring so the usual trick of putting ntpdate
in a cron is not a good solution since it throws all the graphs off
and causes false alerts and regular ntp is frustratingly stubborn
about refusing to correct large clock skew.

I can't seem to find any documentation on how these tools work or how
to configure them to keep time synced with the host.

Any help would be appreciated.

-- 
John Lange
www.johnlange.ca

Re: Time keeps on slippin slippin slippin slippin... into the future...

[Eric S. <ej...@sh...>]

On 11/24/2010 09:15 AM, John Lange wrote:
> Just like the song says, the time on my SLES 11 server "keeps on
> slippin slippin slippin... into the future..."
>
> The vmware-guestd are started at boot and are running.
>
> The following modules are loaded:
>
> # lsmod |grep vm
> vmsync                  5440  0
> vmmemctl               10188  0
> vmblock                15124  1
>
> Yet clocks keeps skewing forward at a rapid pace.
>
> This VM is used for monitoring so the usual trick of putting ntpdate
> in a cron is not a good solution since it throws all the graphs off
> and causes false alerts and regular ntp is frustratingly stubborn
> about refusing to correct large clock skew.
>
> I can't seem to find any documentation on how these tools work or how
> to configure them to keep time synced with the host.
>
> Any help would be appreciated.
>

See 
http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1006427&sliceId=1&docTypeID=DT_KB_1_1&dialogID=23956052&stateId=1%200%2023952415

"Note: In all cases use NTP instead of VMware Tools periodic time 
synchronization."

-- 
-Eric 'shubes'

Re: Time keeps on slippin slippin slippin slippin... into the future...

[John L. <jo...@jo...>]

On Wed, Nov 24, 2010 at 6:31 PM, Eric Shubert <ej...@sh...> wrote:
> See
> http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1006427&sliceId=1&docTypeID=DT_KB_1_1&dialogID=23956052&stateId=1%200%2023952415

I don't know when that was published but I've been looking for a
document like that from VMWare for a long time.That is excellent
information, thank you.

One question, is it "tinker panic 0" ? Or "setvar panic 0" ? I found
the latter in an ntp.conf man page and ntp does not complain about it.

Is it different depending on the ntp version?

Mine is:

# ntpd --version
ntpd - NTP daemon program - Ver. 4.2.4p6

Thanks

John

Re: Time keeps on slippin slippin slippin slippin... into the future...

[Eric S. <ej...@sh...>]

On 11/24/2010 10:17 PM, John Lange wrote:
> On Wed, Nov 24, 2010 at 6:31 PM, Eric Shubert<ej...@sh...>  wrote:
>> See
>> http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1006427&sliceId=1&docTypeID=DT_KB_1_1&dialogID=23956052&stateId=1%200%2023952415
>
> I don't know when that was published but I've been looking for a
> document like that from VMWare for a long time.That is excellent
> information, thank you.
>
> One question, is it "tinker panic 0" ? Or "setvar panic 0" ? I found
> the latter in an ntp.conf man page and ntp does not complain about it.
>
> Is it different depending on the ntp version?
>
> Mine is:
>
> # ntpd --version
> ntpd - NTP daemon program - Ver. 4.2.4p6
>
> Thanks
>
> John
>
> ------------------------------------------------------------------------------

I don't know for sure. Looking at "man ntp_misc", it says that setvar 
adds an additional system variable. tinker is documented there as well.

Given that the tinker variable already exists, I'm not sure what would 
happen upon execution with setvar. setvar might work, but it might not 
do what you desire. I'd use tinker.

(using ntp-4.2.2p1-9.el5.centos.2.1 here)

-- 
-Eric 'shubes'

Re: Time keeps on slippin slippin slippin slippin... into the future...

[John L. <jo...@jo...>]

I changed it to tinker and I'm still gaining time like crazy. 20
minutes in less than 24 hours. Similar to the results with setvar.

I've turned logging up to "all" so maybe that will reveal something.

-- 
John Lange
www.johnlange.ca

Re: Time keeps on slippin slippin slippin slippin... into the future...

[Eric S. <ej...@sh...>]

On 11/25/2010 07:00 PM, John Lange wrote:
> I changed it to tinker and I'm still gaining time like crazy. 20
> minutes in less than 24 hours. Similar to the results with setvar.
>
> I've turned logging up to "all" so maybe that will reveal something.
>

Is the host keeping time reliably? What software is the host running?
(distro/ver/vmware/ver)

Are there any guest kernel settings related to time being used?

-- 
-Eric 'shubes'