Re: Kernel 2.6.15.1 + NFS is 4 times slower than FTP!?

From: Justin Piszcz
Date: Tue Jan 17 2006 - 13:22:56 EST


Alan, is it normal for FTP to be 2x as fast as NFS?
With 100mbps, I never seemed to have any issues, but with GIGABIT I definitely see all sorts of weird issues.


On Tue, 17 Jan 2006, Alan Cox wrote:

On Maw, 2006-01-17 at 18:48 +0100, Tomasz KÅoczko wrote:
I wonder how much faster NFS over TCP would be, or if NFS in the kernel is
the problem itself?

On Linux NFS over TCP is slower than over UDP ~10%.

For the specific case you measured. Its never quite that simple because
behaviour over different networks and error patterns varies a lot and
TCP can be a big win on loaded networks or under error conditions,
especially packet loss, where fragmentation losses kill throughput on
UDP.