Hello, fellow timekeepers, > You really want your time sources to be "real" physical > systems as much as possible, as virtualization inherently > offers much worse timing than an OS running on bare metal.
Oh well! Thanks to Ryan for what may well be good advice (I am not sure and I cannot tell) - provided you have the choice to follow it. On the other hand, if you don't, don't worry, don't bother. If a virtual machine is what you have, do not hesitate to put an ntpd on it. And do not hesitate to add that to the pool, either. At least that's what I do. A virtual machine is the only thing I run that's connected to the internet and has a stable IP number. From the monitoring page at http://www.pool.ntp.org/scores/109.75.188.245 , it seems to consistently stay be within +/- 10 ms. And that is only within the precision of the monitoring process, which is known to be limited. Upon being asked, my ntpd itself has this to say: $ ntpdc -c kerninfo pll offset: 0.000145 s pll frequency: -0.526 ppm maximum error: 0.069376 s estimated error: 0.001136 s status: 0001 pll pll time constant: 10 precision: 1e-06 s frequency tolerance: 500 ppm This may be worse than what you could do with bare iron. Or maybe I already get the precision that's possible, given the machine's network connection. I am not sure. But then, it does not matter all that much to me. What does matter to me is what I hand out to the world: $ ntpdc -c sysstat time since restart: 12349870 time since reset: 12349870 packets received: 613732613 packets processed: 52763 current version: 312114698 previous version: 295896455 declined: 611 access denied: 14085 bad length or format: 5747856 bad authentication: 41186 rate exceeded: 96461802 Some 43 times per second (pun obviously intended). Regards, Andreas P.S.: For the record: I don't want to talk against Ryan's warning regarding interconnecting various ntpd instances that _run on the same underlying hardware_. That warning stands utterly unaffected by anything I've written. I just want to make the point that an ntpd on a virtual machine can be a valuable pool member. _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
