>> Other possibilities might be if the ahc driver got messed up so it
>> doesn't reliably work with multiple controllers.  Or somehow the
>> PCI-PCI bridge, on the 3940UW, is getting in the way (even though it
>> isn't on 1.2).

>This, at least, could be tested by running concurrent fscks on the 4
>altroots or something like:
># for i in 1 2 3 4 ; do dd if=/dev/rsd${i}d of=/dev/null bs=1024k & done

The ccd driver seems to be exonerated for now... :-)

Both running parallel fsck's, and parallel dd's locked up the system
tight.  I didn't even have ccd configured during the tests, so it's
not a factor.

Back to the hardware.  A 2940UW and a dual-channel 3940UW, with five
SCSI hard drives, plus a jaz drive, spread across them (I used all six
drives during the parallel-dd test).  There is also a SCSI CD-ROM and
a SCSI DAT driver, which aren't really involved.

It should be noted that because there are so many controllers, plus a
SMC EtherPower PCI (DEC 21140 chip), that there are at least two PCI
interrupts being shared.  It should also be noted that this doesn't
cause any problems under NetBSD-1.2.

Any more ideas?  Bug in the ahc driver?  Bug with sharing PCI-PCI
interrupts, and/or PCI bridges (there are two of them in the system)?

To give more info on the installed hardware, here's the dmesg output
from booting my 1.2+ kernel:

NetBSD 1.2 (MINDBENDER) #417: Tue Mar 11 21:47:49 PST 1997
    michaelv@MindBender.serv.net:/u/src/sys/arch/i386/compile/MINDBENDER
CPU: i486DX (486-class CPU)
real mem  = 66715648
avail mem = 53395456
using 2430 buffers containing 9953280 bytes of memory
mainbus0 (root)
isa0 at mainbus0
com0 at isa0 port 0x3e8-0x3ef irq 9: ESP, 1024 byte fifo
com1 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com2 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37f: polled
lpt1 at isa0 port 0x278-0x27f: polled
npx0 at isa0 port 0xf0-0xff: using exception 16
vt0 at isa0 port 0x60-0x6f irq 1: unknown s3, 80 col, color, 9 scr, mf2-kbd, [R3.32]
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
pci0 at mainbus0 bus 0: configuration mode 1
vendor Intel, unknown product 0x122d (class bridge, subclass host, revision 0x02) at pci0 dev 0 function 0 not configured
vendor Intel, unknown product 0x122e (class bridge, subclass ISA, revision 0x02) at pci0 dev 7 function 0 not configured
de0 at pci0 dev 9 function 0: DC21140 [10-100Mb/s] pass 1.2
de0: Ethernet address 00:00:c0:87:87:e5
de0: enabling 10baseT UTP port
de0: interrupting at irq 15
ahc0 at pci0 dev 10 function 0
ahc0: interrupting at irq 12
ahc0: Reading SEEPROM...done.
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
ahc0: Reseting Channel A
ahc0: Downloading Sequencer Program...Done
scsibus0 at ahc0
ahc0: target 0 synchronous at 10.0MHz, offset = 0xf
ahc0: target 0 Tagged Queuing Device
sd0 at scsibus0 targ 0 lun 0: <COMPAQPC, DPES-30540, S31K> SCSI2 0/direct fixed
sd0: 511MB, 4901 cyl, 2 head, 106 sec, 512 bytes/sec
ahc0: target 2 synchronous at 4.0MHz, offset = 0xf
cd0 at scsibus0 targ 2 lun 0: <SONY, CD-ROM CDU-55S, 1.0t> SCSI2 5/cdrom removable
ahc0: target 3 synchronous at 10.0MHz, offset = 0xf
ahc0: target 3 Tagged Queuing Device
sd1 at scsibus0 targ 3 lun 0: <iomega, jaz 1GB, J.83> SCSI2 0/direct removable
sd1: sd1(ahc0:3:0): illegal request, data = 03 9a 01 37 d6 00 00 00 20 20 00 00 00 00 00 00 00
sd1: could not mode sense (4); using fictitious geometry
1021MB, 1021 cyl, 64 head, 32 sec, 512 bytes/sec
ahc0: target 4 synchronous at 5.0MHz, offset = 0xf
st0 at scsibus0 targ 4 lun 0: <ARCHIVE, IBM4326NP/RP  !D, 4.AC> SCSI2 1/sequential removable
st0: drive empty
ahc0: target 5 synchronous at 10.0MHz, offset = 0xf
ahc0: target 5 Tagged Queuing Device
sd2 at scsibus0 targ 5 lun 0: <HP, C3323-300, 5011> SCSI2 0/direct fixed
sd2: 1003MB, 2982 cyl, 7 head, 98 sec, 512 bytes/sec
ppb0 at pci0 dev 11 function 0: Digital Equipment DECchip 21050 PCI-PCI Bridge (rev. 0x02)
pci1 at ppb0 bus 1
ahc1 at pci1 dev 4 function 0
ahc1: interrupting at irq 10
ahc1: Reading SEEPROM...done.
ahc1: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
ahc1: Reseting Channel A
ahc1: Downloading Sequencer Program...Done
scsibus1 at ahc1
ahc1: target 6 synchronous at 10.0MHz, offset = 0xf
ahc1: target 6 Tagged Queuing Device
sd3 at scsibus1 targ 6 lun 0: <SEAGATE, ST31200N, 8648> SCSI2 0/direct fixed
sd3: 1006MB, 2700 cyl, 9 head, 84 sec, 512 bytes/sec
ahc2 at pci1 dev 5 function 0
ahc2: interrupting at irq 12
ahc2: Reading SEEPROM...done.
ahc2: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
ahc2: Reseting Channel A
ahc2: Downloading Sequencer Program...Done
scsibus2 at ahc2
ahc2: target 5 synchronous at 10.0MHz, offset = 0xf
ahc2: target 5 Tagged Queuing Device
sd4 at scsibus2 targ 5 lun 0: <HP, C3323-300, 5011> SCSI2 0/direct fixed
sd4: 1003MB, 2982 cyl, 7 head, 98 sec, 512 bytes/sec
ahc2: target 6 synchronous at 10.0MHz, offset = 0xf
ahc2: target 6 Tagged Queuing Device
sd5 at scsibus2 targ 6 lun 0: <SEAGATE, ST31200N, 8630> SCSI2 0/direct fixed
sd5: 1006MB, 2700 cyl, 9 head, 84 sec, 512 bytes/sec
S3 968 (class display, subclass VGA, revision 0x00) at pci0 dev 12 function 0 not configured
biomask 1440 netmask 9440 ttymask 965a
sd1(ahc0:3:0): illegal request, data = 0c 29 01 37 d6 00 00 00 ff ff 00 00 00 00 00 00 00
sd1: could not mode sense (4); using fictitious geometry

 Aperture driver for XFree86 version 1.5


-----------------------------------------------------------------------------
  Michael L. VanLoon                           michaelv@MindBender.serv.net
      Contract software development for Windows NT, Windows 95 and Unix.
             Windows NT and Unix server development in C++ and C.

        --<  Free your mind and your machine -- NetBSD free un*x  >--
    NetBSD working ports: 386+PC, Mac 68k, Amiga, Atari 68k, HP300, Sun3,
        Sun4/4c/4m, DEC MIPS, DEC Alpha, PC532, VAX, MVME68k, arm32...
    NetBSD ports in progress: PICA, others...
-----------------------------------------------------------------------------