I just booted a Dell PowerEdge 2950 with

  NetBSD 4.99.17 (INSTALL_LARGE) #3: Thu Apr 12 15:03:11 BST 2007

all was fine - dhclient, completed tiny ftp transfer, went away, and came
back to find:

WARNING: mclpool limit reached; increase NMBCLUSTERS
panic: bnx0: Double mbuf allocation failure!

... panic? Of course with nothing handy to plug into the serial port, I
can't do much at the db> prompt - the USB keyboard clearly doesn't respond.

Cheers,

Patrick