mj <lists@xxxxxxxxxxxxx> 于2019年4月25日周四 下午6:34写道： > > Hi all, > > On our three-node cluster, we have setup chrony for time sync, and even > though chrony reports that it is synced to ntp time, at the same time > ceph occasionally reports time skews that can last several hours. > > See for example: > > > root@ceph2:~# ceph -v > > ceph version 12.2.10 (fc2b1783e3727b66315cc667af9d663d30fe7ed4) luminous (stable) > > root@ceph2:~# ceph health detail > > HEALTH_WARN clock skew detected on mon.1 > > MON_CLOCK_SKEW clock skew detected on mon.1 > > mon.1 addr 10.10.89.2:6789/0 clock skew 0.506374s > max 0.5s (latency 0.000591877s) > > root@ceph2:~# chronyc tracking > > Reference ID : 7F7F0101 () > > Stratum : 10 > > Ref time (UTC) : Wed Apr 24 19:05:28 2019 > > System time : 0.000000133 seconds slow of NTP time > > Last offset : -0.003333524 seconds > > RMS offset : 0.003333524 seconds > > Frequency : 12.641 ppm slow > > Residual freq : +0.000 ppm > > Skew : 0.000 ppm > > Root delay : 0.000000 seconds > > Root dispersion : 0.000000 seconds > > Update interval : 1.4 seconds > > Leap status : Normal > > root@ceph2:~# > > For the record: mon.1 = ceph2 = 10.10.89.2, and time is synced similarly > with NTP on the two other nodes. > > We don't understand this... > > I have now injected mon_clock_drift_allowed 0.7, so at least we have > HEALTH_OK again. (to stop upsetting my monitoring system) > > But two questions: > > - can anyone explain why this is happening, is it looks as if ceph and > NTP/chrony disagree on just how time-synced the servers are..? Not familiar with chrony, but for our practice is using NTP, and it works fine. > - how to determine the current clock skew from cephs perspective? > Because "ceph health detail" in case of HEALTH_OK does not show it. > (I want to start monitoring it continuously, to see if I can find some > sort of pattern) You can use 'ceph time-sync-status' to get current time sync status. > > Thanks! > > MJ > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Thank you! HuangJun _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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