On Wed, 10 Aug 2011 17:20:12 -0400 (EDT) Jake Smith wrote: [Huge snip] > > > I tuned my MTU setting on the direct link bond to 9000 and saw a 10% > improvement on throughput. Negligible on latency though. > > I was getting consistent 180-185MB/s using the throughput testing script > in the DRBD Users guide with mtu 1500. Iperf was 1.75-1.85Gb/s. After > changing MTU I get 198-99MB/s consistently and highs at 209-215MB/s. > Without DRBD my storage controller is delivering 225MB/s so now there's > almost no cost on the throughput side. Iperf was rock solid at > 1.97-1.98Gb/s repeatedly. >
These numbers match my similar (dual GigE balance-RR replication link) setup. And if you look back in the archives you can find my numbers for quad GigE balance-RR link). What is more than puzzling to me are these write speeds: - Initial resync happens at near wire-speed (rate was set to 200MB/s, ethstats output confirms this speed). - A makefs (ext4) happens at about the same speed (staring at ethstats). - A bonnie++ run on the mounted ext4 fs of the DRBD device clocks in at about 130-150MB/s depending on trailing winds and phase of the moon. This bonnie result matches what I see from ethstats. - The same bonnie++ run on the underlying backing device delivers about 350MB/s. So what is different when a FS is mounted as opposed to the raw (DRBD) device? Where are those 50MB/s hiding or getting lost? Regards, Christian -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ drbd-user mailing list drbd-user@lists.linbit.com http://lists.linbit.com/mailman/listinfo/drbd-user
