Analyzing dropped packets

[Michael Green]

On Wed, Mar 11, 2009 at 11:36 AM, Aviv Greenberg <avivgnet at gmail.com> wrote:
> What is the server used for? What traffic is comming into the server
> (small packets? full MTU?)? at what rate? How many RX descriptors is
> your driver set for? Do you have 802.3X flow control enabled (both
> ends)? Do you see any abnormal CPU usage when the packet drops occur?
>

I'm not quite sure how to check out all these things...

The server is doing backups. Naturally most of the traffic happens
during night hours.


> But more fundementally, why are you even concerned with 2916/689587830
> packet drops? On most scenarious, this is pretty normal behaviour.
>
I'm concerned because occasionally the backup application shuts its
TCP port on which it listens. It seems to happen after a considerable
amount of drops/errors have accumulated on the interface. The only way
out then is to recycle the app. I suspect that these errors might be
the indication of the problem that causes abnormal application
behavior.


> i would be more curious why there are 2900 errors :)
>

I realize there might be a million different reasons for these errors.
How can I investigate them?