Quoting Brian Buhrow,

> 	Hello fellow NetBSD users.  I have a production 1.2.1 NetBSD/Sparc
> machine I set up for nfs serving to an old Microvax we have here running
> Ultrix 4.2.  The NetBSD machine is an IPC with three disks striped on a
> ccd, which is then exported to nfs space.
> 	The symptom is that when the Ultrix machine engages in heavy i/o, or
> at least as heavy as it gets from an old VAX, the nfsds lock up in disk
> wait in the kernel.  The  wchan for the processes is:
> "143748"
> the priority is -20.

A numeric wchan doesn't provide much information.. is that really
what ps says? Or top? If so, is your ps binary up to date? The
wchan name is really needed to get any further in analyzing this problem.

- Frank