Re: Help with igb driver/nics, strange issue.

joe wrote:
> I have 3 boxes, each with two nics. One nic for the private network and 
> one for the public network.
> The private network is all on the same vlan. All 6 nics are on the same 
> switch. All connections are 1000tx Full Duplex.
> 
> I will call the servers Box A, Box B, and Box C.
> 
> When i FTP data between Box A & B i get abou 25MB/sec.
> When i FTP data from Box C to Box A or B, i get about 20MB/sec.
> When i FTP data from Box A to C i get 10MB/sec
> When i FTP data from Box B to C i get 200KB/sec...
> 
> Can anyone suggest why i might only be getting 200KB when transfering 
> data from Box B to C but not when transferring data from Box A to C?

Is the hardware exactly the same on all 3 hosts?  From your enumeration
it looks like there's something special about box C.

How busy are the disks?  One of the problems with FTP, at least the
last time I tried to use it for benchmarking was that it used tiny,
tiny transfers to and from disk.  Strangely scp did better even
with the crypto overhead.  Have you tried using netperf to test the
network performance?

Have you checked your cables?  I've seen all sorts of wierd problems
caused by cables.  netstat -ni should give an idea of transmission
problems.  If the switch is a managed switch, you can also check
its interface counters.

Ian

--
Ian Freislich