On 03/29/2012 03:30 PM, Harry Mangalam wrote: > I'm doing some perf tests on a small gluster filesystem - 5 bricks on 4 > servers, all single-homed on the private net. > > I've spawned up to 70 simultaneous jobs on our cluster nodes writing files of > various sizes from /dev/zero to the gluster fs to see what the effect on the > aggregate bandwith and the data is slightly unbelievable in that it seems to > exceed the theoretical max of the network. (I used /dev/zero instead of > /dev/urandom since /dev/urandom couldn't generate data fast enough. > > The 35,000 files of the right size do hit the filesystem (of course they're all > zero's) but the speed at which they transfer exceeds (by quite a bit) the > theoretical max of a 1 Gb network. > > Does gluster (or anything else) do transparent compression? What else would > explain this oddity? How do you define "theoretical max of a 1Gb network"? If it's a switched network, the actual maximum throughput depends on the capabilities of the switch but is likely to be far in excess of 1Gb/s. Could that be it? Could you give more detail about the actual traffic patterns and results? BTW, this is my favorite message title ever. Thanks for that. :)
