NetBSD 6.1 NFS server performances

["Emile `iMil' Heitor" <imil%home.imil.net@localhost>]

Continuing on the NAS performances topic, now it's NFS server's turn.
First things first, I've checked both network and disk throughput, neither cause
a bottleneck:

tatooine is the client
coruscant is the server

$ iperf -c coruscant -p 2828 -t 10
------------------------------------------------------------
Client connecting to coruscant, TCP port 2828
TCP window size: 43.8 KByte (default)
------------------------------------------------------------
[  3] local 192.168.1.1 port 51371 connected with 192.168.1.2 port 2828
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.06 GBytes   908 Mbits/sec

$ dd if=/dev/zero bs=1024K count=1000 | nc -v coruscant 2828
Connection to coruscant 2828 port [tcp/*] succeeded!
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 9.27363 s, 113 MB/s

Gigabit link, all clear.

Now using NFS:

$ dd if=/dev/zero bs=1024K count=1000 >Desktop/nfs@coruscant/imil/tmp/test
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 51.8476 s, 20.2 MB/s

I know, right? And yes results are identical with differents bs values.

I've tried a bazillion NFS options on the clients (TCP, UDP, {r,w}size from 8192
to 64k...), tried many OSes as a client, the NFS results are consistent,
always between 20 and 30MB/s.
NFS server is started via rc.d with the following rc.conf variables:

rpcbind=YES
mountd=YES
nfs_server=YES
nfsd_flags="-6tun 8"
lockd=YES
statd=YES

And yes I tried increasing or reducing thread number.

/etc/exports is pretty simple:

/export -alldirs -noresvport -maproot=root:wheel -network 192.168.1.0/24

I've read an extensive number of "NetBSD NFS server performances" posts here,
applied every suggestion without any luck, any idea would be highly appreciated.

Thanks,

----------------------------------------------------------------
Emile `iMil' Heitor * <imil@{home.imil.net,NetBSD.org,gcu.info}>
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