Well, the consensus answer to my "does anyone have soft updates working
on their NetBSD/alpha system" question appears to be a solid "YES."  
However, all the responses I saw appeared to indicate folks running on
something other than DEC 3000-based systems.

So, is there anyone running NetBSD/alpha on DEC 3000/300 hardware that
has soft updates enabled and working on their system?

To recap, on mine, I get:

>>>>>
fatal kernel trap:

    trap entry = 0x2 (memory management fault)
    a0         = 0x0
    a1         = 0x1
    a2         = 0x0
    pc         = 0xfffffc0000433efc
    ra         = 0xfffffc0000433e48
    curproc    = 0xfffffc0000d3a708
        pid = 4, comm = ioflush

panic: trap
syncing disks... panic: lockmgr: locking against myself

dumping to dev 8,1 offset 158451
dump 112 111 110 [[etc...]]
<<<<<

This is running on a recent -current.

Cheers,

Paul.

e-mail: paul@gromit.dlib.vt.edu

"Without music to decorate it, time is just a bunch of boring production
 deadlines or dates by which bills must be paid."
        --- Frank Vincent Zappa