I'm not sure whether this is related to the sii problems on the 3100 that
Michael Hitch has been hunting recently, but here you go:

During a "make obj depend", rz1 was corrupted with damaged inodes and
other other nastinesses indicating random disk blocks being trashed.
These events were accompanied by the messages and the end of the dmesg
listing below.

The fsck messages included bad file types, incomplete inodes, and
non-contigous directory files.

It took about 4 or 5 fsck -f -y's to make the disk fsck-clean again.

rz2 contains /, swap, and /usr
rz1 contains /usr/src
rz3 contains /home (including /home/obj.pmax).

Any ideas or explanations ?

regards
Erik Bertelsen
------------------

NetBSD/pmax-current as of yesterday.

Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.2E (AARHUS1) #17: Sat May 24 22:29:12 MEST 1997
    erik@aarhus1.uni-c.dk:/usr/src/sys/arch/pmax/compile/AARHUS1
real mem = 25165824
avail mem = 20729856
using 614 buffers containing 2514944 bytes of memory
mainbus0 (root)
cpu0 at mainbus0: MIPS R3000 CPU Rev. 2.0 with MIPS R3010 FPC Rev. 2.0
(configuring kn01/5100 baseboard devices)
configuring pm at afc00000 interrupt number 3
pm0 at mainbus0 (1024x864x1) (console)
configuring dc at bc000000 interrupt number 2
dc0 at mainbus0 (kn01: intr_establish hardcoded) 
configuring lance at b8000000 interrupt number 1
le0 at mainbus0: address 08:00:2b:23:c4:89
le0: 32 receive buffers, 8 transmit buffers
 (kn01: intr_establish hardcoded) configuring sii at ba000000 interrupt number 0
sii0 at mainbus0 (kn01: intr_establish hardcoded) 
configuring mc146818 at bd000000 interrupt number 16
clock0 at mainbus0
configuring dc at b5000000 interrupt number 4
configuring dc at b5200000 interrupt number 5
configuring  at 0 interrupt number 0
autconfiguration done, spl back to 0x0
Beginning old-style SCSI device autoconfiguration
rz1 at sii0 drive 1 slave 0 DEC RZ24     (C) DEC rev 211B, 409792 512 byte blocks
rz2 at sii0 drive 2 slave 0 DEC RZ24     (C) DEC rev 211B, 409792 512 byte blocks
sii_DoSync: len 3 per 64 req/ack 15
rz3 at sii0 drive 3 slave 0 DEC RZ56     (C) DEC rev 0400, 1299174 512 byte blocks
tz0 at sii0 drive 5 slave 0 GENERIC SCSI tape device: qual 0x30, ver 1
rconsattach: 1 raster consoles
boot device: rz2
mountroot: trying ffs...
root file system type: ffs
init: copying out path `/sbin/init' 11
rz1: error 0 scsi status 0x2
rz1: Illegal request
rz1: error 0 scsi status 0x2
rz1: Illegal request
rz1: error 0 scsi status 0x2
rz1: Illegal request
rz1: error 0 scsi status 0x2
rz1: Illegal request