Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
2014-04-11 14:03 GMT+02:00 Ben RUBSON <ben.rubson at gmail.com>: > 2014-04-11 12:30 GMT+02:00 Steve Thompson wrote: > >> On Fri, 11 Apr 2014, Ben RUBSON wrote: >> >> Replication link is a a 10 Ge link, throughput with iperf (6 threads or >>> more) gives 7.7 Gb/s (918 MB/s) bidirectional. >>> Could be tuned, but well, enough to sustain my RAID array at 680 MB/s. >>> Latency of 10.8 ms between the 2 servers. >>> MTU 9012. >>> >> >> Something that strikes me is your latency and throughput: assuming it is >> not a typo, that latency is remarkably high. Between two of my 10GbE >> servers, I see an average latency of 0.07ms (from ping) and an iperf >> throughput of 9.8 Gb/s with MTU=9000 and 1 thread. >> > > Yes I did not tell that replication link is a long distance link, the 2 > servers are separated by hundreds of kilometers :-) > Which explains the 10.8 ms latency. > > I made further tests, and seems that my issue is that I did not tune my > TPC stack according to the 10 G speed. > However, with tuning (window size &co), I did not manage to go beyond 7.3 > Gb/s (iperf, 1 thread). > Without tuning I was at 2.15 Gb/s (iperf, 1 thread). > OK, just to clarify, my long distance link provider just told me that I won't be able to go beyond. So, TPC stack tuning was the initial issue here. Hope this will help others playing with 10G :-) Thank you again, Best regards, Ben -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20140411/9e12e496/attachment.htm>