Toru,

First of all, many thanks for your help. As I am out of the country at the
moment and away from the machine until Saturday I wont be able to answer
all questions exactly, but I'll give you the best approximation for the
moment..

> Can we have what 'cnfg 3' reports and the boot message of your kernel?

Unfortunately, I can't read the console output remotely but from memory
'cnfg 3' reports (relevant bits thereof) that it has found the scsi
controller, 3 disks and 1 tape device (Sony SDT-9000 a DDS3 4mm tape
device with a scsi id set to 5). 

Here is the dmesg output:

Copyright (c) 1996, 1997, 1998, 1999, 2000
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.4.2 (UNA) #0: Thu Apr 27 17:38:28 BST 2000
    root@una:/tmp_mnt/krka.internal.net/export/NetBSD/src/sys/arch/pmax/compile/UNA
DECstation 5000/133 (3MIN)
real mem  = 50331648
avail mem = 41963520
using 1228 buffers containing 5029888 bytes of memory
mainbus0 (root)
cpu0 at mainbus0: cpu0: MIPS R3000 CPU Rev. 3.0 with MIPS R3010 FPC Rev. 4.0
cpu0: 64kb Instruction, 128kb Data, direct mapped cache
tc0 at mainbus0: 12.5 MHz clock
ioasic0 at tc0 slot 3 offset 0x0
le0 at ioasic0 offset 0xc0000: address 08:00:2b:2c:d0:02
le0: 32 receive buffers, 8 transmit buffers
scc0 at ioasic0 offset 0x100000
scc1 at ioasic0 offset 0x180000
mcclock0 at ioasic0 offset 0x200000: mc146818 or compatible
asc0 at ioasic0 offset 0x300000: target 7
sfb0 at tc0 slot 0 offset 0x0: (1280x1024x8) (console)
Beginning old-style SCSI device autoconfiguration
rz0 at asc0 drive 0 slave 0 DEC RZ25     (C) DEC rev 0700
rz0: 406MB, 1476 cyl, 9 head, 62 sec, 512 bytes/sect x 832527 sectors
rz1 at asc0 drive 1 slave 0 DEC RZ25     (C) DEC rev 0700
rz1: 406MB, 1476 cyl, 9 head, 62 sec, 512 bytes/sect x 832527 sectors
asc_intr: tgt 3 command phase TC zero with non-empty fifo 2
rz3 at asc0 drive 3 slave 0 QUANTUM FIREBALL1280S rev 630C
rz3: 1222MB, 4135 cyl, 4 head, 151 sec, 512 bytes/sect x 2503872 sectors
boot device: rz0
root on rz0a dumps on rz0b
root file system type: ffs

> > Also, I am having difficulties with /sbin/dump (dumping to either a local
> > or a NFS disk) - it just hangs at random points in random filesystems...
> 
> Do you see any differences for /sbin/dump 0uf /dev/null <YOUR_RAWFS>?

*** It would appear that dumping to /dev/null to works fine. N.B. I
modified the above statement with a -B 2000000 switch/value...

--Nino