On 2017/09/15 19:45, Andreas Krüger wrote: > I see that. But it still does not answer the question why the option to set > them through sysctl was removed. Why would you suddenly not be allowed to set > the max size with sysctl, what is the reason behind that choice taken in the > 4.9 release.
Before then it was a fixed size buffer. Whatever you set the sysctl to, it was static and didn't rise. After then it was auto tuning so that connections that could make use of increased buffer sizes could do so, but without blowing out kernel memory use excessively. > > > Den 15. sep. 2017 kl. 13.34 skrev Stuart Henderson <s...@spacehopper.org>: > > > >> On 2017-09-14, Chris Cappuccio <ch...@nmedia.net> wrote: > >> -w1M works for me > >> - > >> Andreas Kr??ger [a...@patientsky.com] wrote: > >>> I do manage to read the manual, but let me clarify this. I am not > >>> allowed to set a buffer larger than 256KB with iperf: > >>> > >>> $ uname -a > >>> OpenBSD odn1-fw-odn1-01 6.0 GENERIC.MP#0 amd64 With a hostname like this it sounds like a firewall. Are you aware that this only affects connections to/from the machine itself? It has no effect on forwarded connections. > > 6.0 is limited to 256K, 6.1 and newer allow up to 2MB, and by default > > it will auto tune. > > > > As well as iperf -w, here's how to hardcode it on a few other programs: > > > > httpd/relayd "socket buffer" > > tcpbench -S > > rsync --sockopts=SO_SNDBUF=xxx,SO_RCVBUF=yyy > > > > You might be interested to watch "netstat -Bn -p tcp" if you're playing > > with this.. > > > >
