Re: [nfsv4]nfs client bug

[Benny Halevy <bhalevy@tonian.com>]

Hi,

First, please use plain text only when sending to linux-nfs@vger.kernel.org
as multi-part / html messages are automatically blocked by the spam filter.

I'm not so sure that the nfs client is to blame for the performance
you're seeing.  The problem could arise from too small of a block size
by dd / iozone

I'd try:
a. using a larger block size (e.g.  dd bs=4096k)
b. tuning your tcp better for high bandwidth
c. using jumbo frames all the way, and making sure that the mtu is discovered
automatically and set properly to 9000.

Also, what's you network look like?
what's the switch you're using
is it indeed 10 Gbps non-blocking
are there any linecard / chip bottlenecks or over subscription

Do you see better throughput with iperf?

Brian, you's probably have even more tips and tricks :)

Regards,

Benny

On 2011-06-28 11:26, quanli gui wrote:
> Hi,
> Recently I test the nfsv4 speed, I found that there is something wrong in
> the nfs client, that is the one nfs client can only provide 400MB/S to the
> server.
> My tests as follow:
> machine:one client, four server; hardware: all 16core, 16G memory, 5T disk;
> os: all suse 11 enterprise server, 2.6.31-pnfs-kernel; network: client,
> 10GE, server, 2GE(bond, 1GE*2);
> test method: on the client, mkdir four independent directory, mount the four
> server via nfsv4 protocol, every time increase one;
> test tool: iozone, or dd if=/dev/zero of=test count=20K,then cat
> test>/dev/null
> test result:(force on read speed, and watch the client/server network
> input/output by the sar command)
> 1 client vs 1 server: 200MB/S
> 1 client vs 2 server: 380MB/S, every server: 190MB/S
> 1 client vs 3 server: 380MB/S, every server: 130MB/S
> 1 client vs 4 server: 385MB/S, every server: 95MB/S
> 
> From above, we found that 400MB/S is the max-speed for one client. This
> speed is the limition? How to increase this speed?
>