On Mar 22, 2013, at 6:32 PM, Richard Kearsley <rkears...@blueyonder.co.uk> wrote: > Hi > > I'm trying to tune 'kern.maxbcache' with hope of increasing 'vfs.maxbufspace' > so that more files can be stored in buffer memory on freebsd 9.1 > It's suggested to tune this value here > http://serverfault.com/questions/64356/freebsd-performance-tuning-sysctls-loader-conf-kernel > and here http://wiki.nginx.org/FreeBSDOptimizations > However, I can't get the value of 'vfs.maxbufspace' to increase: > kern.maxbcache: 21474836480 > vfs.maxbufspace: 3441033216
I assume that you have 9.1 amd64, the following applies only to amd64. On amd64 maxbcache is zero by default and effectively is no-op, thus it doesn't further limit maxbufspace (cf. on i386 it's set to 200MB, due to KVA constraints; and buffer space is reserved in KVM on early boot). The kernel auto-tunes maxbufspace based on the amount of physical memory available using the formula "for the first 64 MB of ram use 1/4 for buffers, plus 1/10 of the ram over 64 MB". So, your current vfs.maxbufspace value corresponds to 32GB RAM and is quite enough. Anyway, you can further increase it by setting kern.nbuf in /boot/loader.conf With your current maxbufspace value, it's kern.nbuf=210024 now. -- Sergey Kandaurov pluk...@nginx.com _______________________________________________ nginx mailing list nginx@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx
