NFS over LAGG / lacp poor performance

[Gerrit Kühn]

On Fri, 25 Apr 2014 15:02:15 +0100 "Steven Hartland"
<killing at multiplay.co.uk> wrote about Re: NFS over LAGG / lacp poor
performance:

SH> We find that large numbers of queues causes high interrupt issues

Like the thing I am seeing with igb1 on my system?

---
root at storage:/root #	vmstat -i
interrupt                          total       rate
irq1: atkbd0                        2743          0
irq18: ehci0 uhci5               4445560          2
irq21: uhci1                          29          0
cpu0:timer                     355724275        227
irq256: igb0:que 0              99437514         63
irq257: igb0:que 1              61534816         39
irq258: igb0:que 2             101725601         65
irq259: igb0:que 3             100864440         64
irq260: igb0:link                      2          0
irq261: igb1:que 0               1689527          1
irq262: igb1:que 1            2357590958       1510
irq263: igb1:que 2               1584474          1
irq264: igb1:que 3               1923144          1
irq265: igb1:link                      2          0
irq266: mps0                   332232450        212
irq267: mps1                   194207894        124
irq268: mps2                   176700834        113
irq269: ahci0                   59175548         37
cpu1:timer                     419838321        268
cpu3:timer                     329696415        211
cpu2:timer                     328219053        210
Total                         4926593600       3156
---


irq262 sticks out like a sore thumb...

SH> however at a guess you did this to enable the machine to boot with
SH> all nics due to lack of auto mbuf tuning in 9.x.
SH> I'd go with ~2 queues per nic.

I was wondering what to try next for my system: either manually set the
queues back to 2 or 1 per NIC, or try upgrading to either 9.2 or 10 as it
looked like there have been improvements in the igb driver. Do you have
any recommendations on that?


cu
  Gerrit