Re: [Ntp] virtual server for ntp server

[Edward Vielmetti <[e-mail]>]

There are at least two reasons you might avoid a virtual machine for an NTP server and prefer something closer to bare metal.

One would be the presence of “noisy neighbors”, other VMs scheduled on the same hardware that steal CPU cycles or impinge on your network or get stalled on I/O or the like. These noisy neighbors could be other processes that you are running on the same physical hardware, but in a VM situation on a shared cloud infrastructure you might get unpredictably bad results as a result of other VMs scheduled on the same hardware that you have no visibility into. The same “noisy neighbor” logic applies to not running benchmarks on VMs because you don’t get the same results twice. Single tenancy helps for accurate clocks.

The other might be deficiencies in the VM’s timekeeping apparatus. An example of this is with the virtual machine system for MacOS called “Lima” which sometimes has bad clock drift, e.g. as described in https://github.com/lima-vm/lima/issues/1307  and also affecting the “Finch” system derived from it at https://github.com/runfinch/finch/issues/248 .

If someone wants to look into the Lima problem it would be welcomed, I am not really sure what’s going on but the lack of good time sync there has gotten in my way enough to make that unusable for my needs.

Thanks and 73 de Ed W8EMV

Edward Vielmetti
Developer Partner Manager, Open Source
Equinix

[e-mail]