I have a storage server running Solaris 11.3 on an SE326M1 (basically, an HP DL180 G6) which has an integrated Intel 85276-based NIC (as far as I can tell, anyway). I've got some highly variable performance on the card and I think I've narrowed down the problem. I've disabled automatic link-speed negotiation and, while running
iperf3, I see that, as soon as a network connection comes in,
vmstat reports that the system is getting around 880 000 system calls per second; speed was anywhere from 100Mbps to 300Mbps. This behaviour is seen when the computer is directly connected to another machine or via a switch; the
iperf3 client was another server; that server has no problem maxing out its network ports at GBe speeds.
The 880 000 system calls per second seems to me to be a very high number and a likely proximal symptom to the problem. I tried the same thing on a different box and saw numbers in the low tens of thousands of system calls per second.
Does anyone have any diagnostic suggestions/solutions? Or am I just unlucky and need to get a different network card? Thanks in advance.