On Tue, Mar 04, 2025 at 06:46:20PM +0000, Eugen Block wrote: > > It's almost always the network ;-) > > I know, I have memorized your famous tweet about Ceph being the best network > monitor 😄 It seems to be ;-) When I spun up my small cluster, I used a noname 10G switch. Ceph complained bitterly amount massive latencies across the board, mostly around one node (hosting OSD, MDS, monitors). Running iperf3 between nodes: - A and B: 10G line speed - A and C: barely 10 MBit/s ... but ethtool says 10G ... WAT? Checked the switch management UI: turns out, one of the ports seemed to be bad, with the error counters going brrrrrrr at high speed. Replacing the switch with a Mikrotik one (keeping the same NICs and DAC cables) solved the problem. Kind regards, Alex. -- "Opportunity is missed by most people because it is dressed in overalls and looks like work." -- Thomas A. Edison _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx