November 5th, 2009

artlebedev poster, 2006-03-17, 2189

netbsd 5

turns out, netbsd is much worse than openbsd as far as network performance is concerned.

first, it appears that no window scaling is implemented or enabled by default on 5.0.

then, it appears that you can't even set the default tcp buffer size to 256K, or stuff simply won't work.

from there, it appears that after you do set the buffer size to something like 224K (net.inet.tcp.recvspace=229376), doing pkg_add kdebase4 will reach the mclpool limit, and your networking capabilities are kaput.

well, yeah, at least this fuck up is documented, but then note that the sysctl variable is not runtime modifiable (at least on i386), so you have to edit the /netbsd with gdb and reboot the system before you can actually have `pkg_add kdebase4` complete.

and, last but not least, i'm quite disappointed in the praised infrastructure of the netbsd project: there's a nice mirror at that I can get 100Mbps from, (Columbia, NY, 19ms away), but it only carries the daily builds and the packages -- I cannot find any decent mirrors that carry git, cvs and the normal ftp files that I would get over 40Mbps from here at UWaterloo.

just fyi: as of now, at UW we have a 1Gbps link to the educational network (including all the US universities) and a 1Gbps link to the internet. both freebsd and openbsd do have the nearby educational mirrors that provide speeds of 100Mbps over here, (at Buffalo, NY, 7ms away) and (MI, 20ms away). note that to get 100Mbps with 224K buffer size you have to be at least as close as 19ms from the mirror.

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