On Sat, November 3, 2018 7:10 pm, Stefan Arentz wrote: > Hi everyone, > > I am having an issue where an OpenBSD VM running on vmd is having > serious clock skew issues. > > I am relatively new to OpenBSD, so I am not sure how to properly debug > this. What I hope is that I can provide a good amount of data and folks > here can give me some hints and ask me for additional information to > get to the root cause of this. > > So first some facts and symptoms: > > - Both Host and Guest are running OpenBSD 6.4. The host runs GENERIC.MP > and the guest GENERIC. > - The host runs 50 guests, all OpenBSD (openbsd.amsterdam) > - Only this VM is having this clock issue (is this correct, or were > there others?) > > - The guest has kern.timecounter.hardware=tsc > - The time on the VM was set with rdate a couple of days ago, and as of > now the VM is running about 4 hours behind. > - ntpd is running (main process, dns engine, ntp engine) > - when started or restarted, ntpd complains about "pipe write error > (from main): No such file or directory" but does seem to start > > - I just ran rdate nl.pool.ntp.org and the date was properly updated > - One minute after running rdate, the clock is already 7 seconds slow > > - The guest also has some severe networking issues. often I cannot type > more than a few characters before a ~15 second delays happens. > Interactive typing is difficult. > - I can SSH into the Host and have none of these issues, ruling out > connectivity issues between me (Toronto) and the Host (Amsterdam) > > It would be easy to blame this on NTPd, which does have an unexplained > error message. However, I think even without running NTPd, the clock > skew should not be this extreme. > > Somehow I have a gut feeling that the clock issues and the networking > issues are related. > > I am root on the VM but I am not on the host. I do have vmctl access. > However, the host admin is friendly (Hi Mischa) and is happy to help to > debug this issue. > > I tried to ktrace ntpd to get more insight in the "pipe write error > (from main): No such file or directory" error but I did not get useful > info out of it. This may be because of my unfamiliarity with those > tools. > > Help appreciated :-) > > S. >
VMM VMs do have clock issues. tsc and ntpd should be enough, though (at least with only a couple VMs it is). Is ntpd doing anything? what does 'ntpctl -sa' say? I think that error is causing ntpd to exit (one of the child procs, if not the whole thing).
