performance tuning of iSCSI and Dell MD3000i

[Andrew Snow]

Hi Miroslav,

have you tried increasing your TCP/IP Window settings at both ends?

In freebsd sysctl.conf:

  kern.ipc.maxsockbuf=1048576
  net.inet.tcp.recvspace=262144
  net.inet.tcp.sendspace=262144


I never had trouble hitting line rate of 1Gbps iSCSI with freebsd, but 
the biggest problem was not speed but what happens if the device times 
out or drops out, it causes FreeBSD to completely crash instead of 
degrading gracefully.


- Andrew