> > Its important we identify what resource saturates in the > IP-over-FC case, > > which doesn't in the other. > > Yes, you're right. > > I should have give more informations about CPU utilization... > There is not really a CPU bottleneck I think. > I didn't use mpstat tool for that, but just top (thanks for your > information, I must admin I didn't know the mpstat tool...). > > So, here are the results with IP over FC : > 19:11:39 CPU %user %nice %system %idle intr/s > 19:11:40 all 0.00 0.00 12.50 87.50 8033.00 > 19:11:40 0 0.00 0.00 4.00 96.00 8033.00 > 19:11:40 1 0.00 0.00 21.00 79.00 8033.00 > > > And with Gigabit ethernet : > > 19:14:49 CPU %user %nice %system %idle intr/s > 19:14:50 all 0.00 0.00 26.00 74.00 14432.00 > 19:14:50 0 0.00 0.00 40.00 60.00 14432.00 > 19:14:50 1 0.00 0.00 12.00 88.00 14432.00 It already looks like there are 50% fewer interrupts to the CPU. Now that could be because the FC pkts are larger than the GigE. Were you using Jumbo frames for GigE? How different are the FC pkts, in terms of size? By the way, is the FTP a read or a write? That is, is it TX traffic or RX traffic on the nodes? You might *not* want to ignore the lesser CPU utilization and fewer interrupts observation. That might hold the key. Is it also possible to test the network bandwidth independent of any disk I/O on the servers? This will narrow down the number of variables in the system. Dheeraj - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
