Slow disk write speeds over network

[Sean Chittenden]

> >...and yet more sysctl's for this:
> >
> >	kern.polling.enable=1
> >	kern.polling.user_frac=50	# 0..100; whatever works best
> >
> >If you've got a really terrible Gigabit Ethernet card, then
> >you may be copying all your packets over again (e.g. m_pullup()),
> >and that could be eating your bus, too.
> 
> Ok, so the end result is that after playing around with sysctl's,
> I've found that the tcp transfers are doing 20MB/s over FTP, but my
> NFS is around 1-2MB/s - still slow.. So we've cleared up some tcp
> issues, but 2yet still NFS is stinky..
> 
> Any more ideas?

I'm using UDP NFS over a 100Mbit/FD link with the following settings
and get about 12-14Mbps:

net.inet.tcp.recvspace=65536
net.inet.tcp.sendspace=65536
kern.maxfiles=65536
kern.ipc.maxsockbuf=2097152
kern.ipc.somaxconn=8192
net.inet.tcp.delayed_ack=0
net.inet.udp.recvspace=65536
net.inet.udp.maxdgram=57344
net.local.stream.sendspace=65536
net.local.stream.recvspace=65536
vfs.nfs.async=1
net.inet.udp.log_in_vain=1
net.inet.icmp.icmplim=20000

I'm not taking into account jumbo frames or anything like that, so you
may want to increase the size of some of these values where
appropriate, but some of these may be a start.  -sc

-- 
Sean Chittenden