em0 freezes on ZFS server

[Gerrit Kühn]

On Thu, 25 Feb 2010 14:59:28 -0800 Jack Vogel <jfvogel at gmail.com> wrote
about Re: em0 freezes on ZFS server:

JV> The failure to "setup receive structures" means it did not have
JV> sufficient mbufs
JV> to setup the RX ring and buffer structs. 

I don't know if this is related, but I updated an amd64 zfs machine with
several em cards from 7.2 to 8-stable yesterday. First it worked fine after
booting, but this morning, at least three of the five em interfaces did
not do much anymore. You could revive them for some seconds with ifconfig
down/up, but they always ceased functioning soon after that (within
seconds).
During debugging (up/down, load/unload if_em etc.) I saw the same error
message as above at some point. I finally gave up and rebooted the
machine. For now, everything appears to be back to normal (but for how
long?).

JV> Not sure why this results in a lockup, but try and increase
JV> kern.ipc.nmbclusters.

I just did that, just to make sure.


cu
  Gerrit