Intel 82580 Stats every other second about dstat HOT 5 CLOSED

It's a driver issue. We have had reports before (not sure if it was this driver) and using a newer driver helped in those cases. If you take a 2 or more second average you'll get correct numbers, it's just that the 1 second granularity fails because the driver doesn't update the counters every second :-(

from dstat.

I had a feeling that was the case.

Im not ultra interested in compiling a new driver just to get around that so I will probably just bump the update interval to 2 on these machines.

Thanks for the help.

from dstat.

An interesting fact is that if you would enable the interrupt stats (and you look in /proc/interrupts the interrupt of your NIC), you'll see that the number of interrupts are updated every second. Which proves that it is not a hardware issue (the hardware is sending/receiving data as fast as it can) but the driver simply doesn't do the bookkeeping every second.

If the interrupt would also skip every second, there might be a more severe hardware/driver issue.

from dstat.

I just wanted to note that this was fixed in the latest Debian build for Wheezy with the kernel below.

Linux s2 3.2.0-4-amd64 #1 SMP Debian 3.2.41-2+deb7u2 x86_64 GNU/Linux

With these controllers

01:00.0 Ethernet controller: Intel Corporation 82580 Gigabit Network Connection (rev 01)
01:00.1 Ethernet controller: Intel Corporation 82580 Gigabit Network Connection (rev 01)

from dstat.

Thanks for the feedback !

from dstat.