em driver input errors

[alexpalias-bsdnet at yahoo.com]

--- On Fri, 9/4/09, Artis Caune <artis.caune at gmail.com> wrote:

> Is it still actual?

Hello.  Yes, this is still actual.

1> netstat -nbhI em0 ; uptime
Name    Mtu Network       Address              Ipkts Ierrs     Ibytes    Opkts Oerrs     Obytes  Coll
em0    1500 <Link#1>      00:14:22:17:80:dc      31G   93M        18T      36G     0        27T     0
 7:50PM  up 23 days, 15:40, 1 user, load averages: 0.84, 1.05, 1.16

The huge number of input errors is due to a 80-100kpps flood we received via that interface, which got the errors/sec numbers up in the 50k/s range for a few minutes.

> You didn't mention if you are using pf or other firewall.

Sorry if I didn't mention it.  I am using pf, but have tried "kldunload pf" and the errors didn't disappear.

> I have similar problem with two boxes replicating zfs
> pools, when I
> noticed input errors.
> After some investigation turns out it was pf overhead, even
> though I
> was skipping on interfaces where zfs sedn/recv.
> 
> With pf enables (and skip) I can copy 50-80MB/s with
> 50-80Kpps and
> 0-100+ input drops per second.
> With pf disabled I can copy constantly with 102 or 93 MB/s
> and
> 110-131Kpps, few drops (because 1 CPU almost eaten).

This is the kind of traffic I am seeing:

Errors/second (5 minute average) per interface:
http://www.dataxnet.ro/alex/errors.png
Packets/second (5 minute average) per interface:
http://www.dataxnet.ro/alex/packets.png

Those graphs were saved a few minutes ago, times are EEST (GMT+3)

I'm sorry I don't have the Mbits/s graphs up, I haven't been collecting that data per interface recently (it's collected per vlan).

Alex