em0 watchdog timeout with nfs

[Jasper Berlijn]

Hi,		

At this moment I'm running FreeBSD 4.11 without any problems. A couple
of times I've tried to upgrade to 6.x but without any luck because of
the watchdog timeout errors on em0 when using nfs.

Mar 30 11:30:48 large kernel: em0: watchdog timeout -- resetting
Mar 30 11:30:48 large kernel: em0: link state changed to DOWN
Mar 30 11:30:51 large kernel: em0: link state changed to UP
Mar 30 11:31:01 large kernel: em0: watchdog timeout -- resetting
Mar 30 11:31:01 large kernel: em0: link state changed to DOWN
Mar 30 11:31:03 large kernel: em0: link state changed to UP
Mar 30 11:31:20 large kernel: em0: watchdog timeout -- resetting
Mar 30 11:31:20 large kernel: em0: link state changed to DOWN
Mar 30 11:31:23 large kernel: em0: link state changed to UP

em0 at pci0:14:0:  class=0x020000 card=0x002e8086 chip=0x100e8086 rev=0x02
hdr=0x00
    vendor   = 'Intel Corporation'
    device   = '82540EM Gigabit Ethernet Controller'
    class    = network
    subclass = ethernet

When I try to copy a large file (1gb) then after a couple of mb's
(100mb) the wachtdog timeout will occur. The system is most of the time
idle. Using debug.mpsafenet="0" in /boot/loader.conf doesn't make any
difference.

Any ideas?

- Jasper