[CentOS] network copy performance is poor (rsync) - debugging suggestions?

On 01/23/2015 11:10 AM, Valeri Galtsev wrote:
> I'm not certain what the problem could be. But enabling jumbo packets
> would be the fist thing I would try

Jumbo frames are an excellent option if your system is spending a lot of 
time processing interrupts, which is why I asked about the "hi" value in 
'top'.  However, jumbo frames aren't free.  You have to set the same MTU 
on ALL of the hardware in a given broadcast domain (LAN).  Because of 
that, you'll typically only see that when interrupt processing has been 
demonstrated as a cost that needs to be reduced.

In this case, CIFS is performing reasonably well without jumbo frames, 
so jumbo frames probably won't solve the problem.