Low NFS transfer speed

[markucz%gmail.com@localhost]

Hi folks,

I have an annoying problem with NFS. Here's the network setup:

Linux NFS server <--- 100 Mbps link ---> NetBSD NFS client

I have this configuration:
- Server is running rpcbind, rpc.nfsd, rpc.lockd, rpc.statd,
  rpc.mountd, rpc.idmapd, rpc.rquotad.
    /etc/exports:
        /export/nfs 192.168.1.0/255.255.255.0(rw,insecure,sync)

- Client is running rpcbind, rpc.lockd, rpc.statd.
    /etc/rc.conf:
        lockd=YES
        statd=YES
        rpcbind=YES
        nfs_client=YES
    /etc/fstab:
        linux:/export/nfs /mnt/nfs nfs rw,tcp,intr,rsize=32768,wsize=32768 0 0

Things work, but all transfers are incredibly slow. I ran tcpdump on the
server side and I got this:

---snip---

16:02:56.053674 IP netbsd.localnet.site.1017 > linux.localnet.site.nfs: . ack 
1337277 win 48836
16:02:56.053687 IP linux.localnet.site.nfs > netbsd.localnet.site.1936942451: 
reply Unknown rpc response code=544499809 1460
16:02:56.053692 IP linux.localnet.site.nfs > netbsd.localnet.site.1952805478: 
reply Unknown rpc response code=1635087471 1460
16:02:56.053697 IP linux.localnet.site.nfs > netbsd.localnet.site.1029448809: 
reply Unknown rpc response code=1718183775 1460
16:02:56.053703 IP linux.localnet.site.nfs > netbsd.localnet.site.1650549611: 
reply Unknown rpc response code=1852059146 1460
16:02:56.053825 IP linux.localnet.site.nfs > netbsd.localnet.site.543518069: 
reply Unknown rpc response code=157708142 1460
16:02:56.053948 IP linux.localnet.site.nfs > netbsd.localnet.site.1835285794: 
reply Unknown rpc response code=540946276 1460
16:02:56.061437 IP netbsd.localnet.site.1017 > linux.localnet.site.nfs: . ack 
1346037 win 40076
16:02:56.061447 IP linux.localnet.site.nfs > netbsd.localnet.site.151587106: 
reply Unknown rpc response code=1229866810 1460
16:02:56.061453 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.061459 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.061464 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.061586 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply 
Unknown rpc response code=7697268 1460
16:02:56.061708 IP linux.localnet.site.nfs > netbsd.localnet.site.1313293644: 
reply Unknown rpc response code=572801864 1460
16:02:56.061832 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.078249 IP netbsd.localnet.site.1017 > linux.localnet.site.nfs: . ack 
1356257 win 62752
16:02:56.078260 IP linux.localnet.site.nfs > netbsd.localnet.site.543257376: 
reply Unknown rpc response code=1869374752 1460
16:02:56.078266 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.078271 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply 
Unknown rpc response code=7697268 1460
16:02:56.078276 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.078400 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.078522 IP linux.localnet.site.nfs > netbsd.localnet.site.1430869024: 
reply Unknown rpc response code=1919251573 1460
16:02:56.078646 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460
16:02:56.078768 IP linux.localnet.site.nfs > netbsd.localnet.site.0: reply ok 
1460

---snip---

I'm not sure I understand tcpdump output well. Does this actually mean that
the NFS server is trying to send data to ports beyond 65535? And if yes, do
you have any idea why? Do you think tweaking timeo might help?

Best regards.