On Thu, 11 Nov 2004 [EMAIL PROTECTED] wrote: > What's happening here? I can download at 1mBps from my crappy P200 MMX > w/ freebsd 4.10 at my lan. This server is a Dual Xeon 2.4Ghz w/ 2GB ram > and a decent hdd. It should saturate the 100mbps, but won't go past > 130kB/s.
That's very slow. > Could this be because the server NIC is an em(4) ? I heard there are > some problems with the em driver under 5.3. Not generally this level of problem. > I don't have polling enabled. sacks on, delayed acks on. > the PF queue: > > queue http_out bandwidth 40Mb priority 5 > [ pkts: 59257 bytes: 88471020 dropped pkts: 0 bytes: 0 ] > [ qlength: 0/ 50 borrows: 0 suspends: 177 ] > > Any ideas of what might be causing the tremendous slowdown ? I think I would follow two avenues in investigation: (1) Look for poor hardware interaction with the OS. In particular, use vmstat -i or systat -vmstat 1 or the like to look for interrupt storms (interrupt delivery in excess of 10,000 interrupts per second per source is usually too big). (2) Check the negotiation of the if_em card to the switch -- if you have a gig-e network, it should be full duplex gig-e. If 100mbps, you might want to force the negotiation using the media option if autonegotiation is having problems. (3) Try selectively removing configured network pieces to see if one is having an unexpected result. I'd begin by disabling pf and see if the bandwidth jumps up. We may be able to isolate the source of the problem to a particular component. (4) Look at CPU consumption -- are you pegging out the CPU or busses with other work or traffic, or does the system have capacity left? A bug or problem elsewhere in the system may be starving the network stack. The performance drop you're seeing is excessive for this scenario, but it's worth checking into. There are some performance optimizations for if_em that were merged to RELENG_5 shortly after the release, but they would generally be measurable only in reduced CPU consumption, not increased network performance at 100mbps speeds on modern hardware. Robert N M Watson FreeBSD Core Team, TrustedBSD Projects [EMAIL PROTECTED] Principal Research Scientist, McAfee Research _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"