Interface throughput - am I hitting the limit?

[Richard I Curtis]

Hein,
It makes sense to me, but only if we were doing int( $4/(1024*128) ) and then again at the end doing let t2=$t2*128/10, but your example has us doing $4/(1024*128) but at the end, we do let t2=$t2*8/10

Was the $4/(1024*128) a typo, or am I still missing the point?

Thanks for your help and time on this one!

[Hein van den Heuvel]

Looks like I have the details wrong.
The 8 was supposed to go with the 128 to make an other 1024... but then it needs to be a division, not a multiplication. Just fill in some example numbers from your systems, verify that number are in reasonable ranges: more than a few hundred to get precision, less then a billion to stay clear from 32 bit overflows.
Good luck!
Hein

[rick jones]

I never have been fond of hardcoding duplex settings, even at 100Mbit. I've not had probalems with autoneg and HP-UX system NICs and HP ProCurve switches... perhaps my autoneg life has been charmed. Anyway...

That there are zeros for outbound discards suggests to me that even if you are close to saturation, you have not exceeded it for any length of time greater than it would take to fill the driver's transmit queue. I thought there was an Outbound Queue Length in the mibstats - didn't notice it in your output. If one is willing to abuse Little's Law:

AvgQueueLen = Utilization/(1-Utilization)

then averaging the queue length over time will give some idea of the outbound utilization of the NIC.

[Richard I Curtis]

Yesterday we were able to restart the app which is showing these errors and since then, we have had no re-occurances of the error message so I am now thinking it was nothing to do with throughput.

Thanks to all of the feedback here I have now amended the script and am getting consistent numbers back.

Rick,
The lack of outbound queue length in the stats I posted seems to be because I did the mibstats_ext - if I do the same but with mibstats, the outbound queue is shown - sometimes it is none zero but never more than 2

Again thanks for everyones help!