Cringe at thought of NTP server on a VM?


#1

Is it just me or does anyone else cringe at the thought that NTP is being served from virtual machines? I get that in this day and age everyone is running servers in the cloud but still… It feels so very very wrong.


#2

Nowadays, this is a baseless fear for all but the most stringent timekeeping requirements. The onus is on anyone saying NTP in VMs is inadequate to produce data demonstrating that this is the case.

I’ve published some data from my experiments which show that VMs are good enough for most use cases (apologies for the long URLs):

If you have the opportunity to run NTP on a dedicated bare metal host, great! But for a lot of shops, this is becoming less desirable for various reasons.


#3

I think most VMs do some behind the scene magic to keep NTP happy and track nicely with the hypervisor.

The bigger issues when it comes to time accuracy is the network, not the server. Network error you are talking about milliseconds, while at the OS level you are only talking about microseconds (when comparing against a non-vm). Of course, if either machine is overloaded then all bets are out the window…


#4

I honestly feel that it’s perfectly fine to help the pool out with a VM. One of the main point of the pool is with load distribution after all.