[ntp:questions] running NTP as server only
unruh at wormhole.physics.ubc.ca
Thu Aug 19 13:55:23 UTC 2010
On 2010-08-19, Rob <nomail at example.com> wrote:
> unruh <unruh at wormhole.physics.ubc.ca> wrote:
>> On 2010-08-19, Rob <nomail at example.com> wrote:
>>> unruh <unruh at wormhole.physics.ubc.ca> wrote:
>>>> On 2010-08-17, folkert <folkert at vanheusden.com> wrote:
>>>>> Is it possible to run the NTP daemon only as a server and not as a
>>>>> local-clock maintainer?
>>>>> Reason: I have a virtual machine which gets its time via the vmware
>>>>> tooling from the hardware server it is running on. Now this virtual
>>>>> machine needs to distribute the time to clients.
>>>> Aarrgdaagh. Why would you have a virtual machine, with its remarkably
>>>> unreliabl e clock serve its time to others?
>>> Some companies are virtualizing all their hardware.
>>> E.g. this is happening where I work as well. All the servers have
>>> been replaced by a number of Vmware ESX machines.
>>> So there is no physical hardware machine left to run as the ntp server.
>> uh, to quote Landauer, all information is physical. All virtual machines
>> MUST also run on physical machines.
> But that does not mean you can run NTP on them.
> E.g. on VMware ESX, you cannot do this.
> (there is an NTP running on the console session, but that is just a
> virtual machine running a Linux variant, it is not running on the
> physical machine either)
An OS on a physical machine running virtual servers really should be
able to discipline the physical clock on the system. It is like saying
that the physical machine has no way of accessing disks.Control of
physical hardware ( and I consider clocks physicsl hardware) should be
the responsibility of the base OS. But my strictures probably do not
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