Re: NFS performances

["J. Lewis Muir" <jlmuir%imca-cat.org@localhost>]

On 5/12/14, 10:03 AM, Emmanuel Dreyfus wrote:
> Hello
>
> I have a NFS setup with both NetBSD 6 client and server over a gigabit
> network. Theperformance seems week, even whle client, server and
> network are almost idle.
>
> The test: time dd if=/dev/zero of=test bs=1024k count=100
>
> Done on the NFS server itself:
>    5.31s real 0.00s user 0.39s system
>
> Done over NFS:
>    9.82s real 0.00s user 0.12s system
>
> The overhead looks huge. This is a UDP mount with a 1500 bytes MTU,
> ping is at 0.8 ms from a virtualized client, ang 0.28 ms for a
> physical one.
>
> Are the numbers reasonable? Should I consider a 59% NFS overhead as
> acceptable, or are there some parameters to tweak?

Hi, Emmanuel.

I have no idea if it will help, but have you tried adjusting
the kernel's UDP send and receive buffer sizes (i.e., for IPv4,
net.inet.udp.sendspace and net.inet.udp.recvspace) with sysctl?

Lewis