What's an appropriate response to "data overrun detected in Data-in phase"?

[David Wolfskill]

I am trying to set up a box to act as a "backup" server (i.e., a
server to perform backups -- not a server to fill the breach left
when an active server falls over, for example).

I note in passing that I have done this sort of thing previously
(with some success); but my attempts to date in the current sequence
have met with decidedly unsatisfactory results.  :-(

Some things that are common to the various attempts:

* There is a "combination" AIT-3 tape drive & autoloader as the only
  devices on the SCSI bus.  (The word "combination" in quotes because
  although it looks like a single box, it contains 2 different SCSI
  targets -- the drive is target 6; the autoloader/robot/changer is
  target 0.)  Well, the SCSI host adapter is also on the SCSI bus.

* The tape drive/autoloader has no options for internal termination;
  rather, it has 2 SCSI connectors; one of these is connected to the
  cable; the other, to a SCSI terminator.

  (Thus, bearing in mind that each 8-bit data channel on each SCSI bus
  should be terminated precisely once at each of its 2 ends, termination
  ought not be too complicated.  Or so I thought.)

* The tape drive/autoloader claims to be "autosensing SE/LVD".


Now some variables, with the most recently-used option last:

* I have tried using both an UltraSPARC 5 (sparc64), running -CURRENT
  as of a few days ago, a similar UltraSPARC 5 running Solaris 9 (but
  I had no user-level programs to drive the hardware; unless OpenBoot's
  "probe-scsi-all" reported the devices, then, I had no assurance that
  the devices were seen).  Most recently, I installed FreeBSD 4.9-RC1
  on a dual-CPU PII-400 box (then built a slightly-customized kernel,
  to take advantage of the other CPU and to support the use of the
  SCSI changer device)).  It is this last that I will be discussing
  in the text below, though it is my recollection that I got similar
  behavior from the UltraSPARC 5 running -CURRENT.

* SCSI host adaptors... I have been trying a few of these.  There was an
  Antares P-0060 (which, though differential, appears to not be LVD).
  The others were Adaptec:  an AHA-2940UW; a couple of SE AAA-131Bs; a
  39160 (though the only PCI slots I have available are 32-bit ones) and
  finally, an SE/LVD AAA-131B.

In the course of working with various SCSI cards, I've become rather
skeptical of the "automatic termination".  I expect it's probably better
than it was several years ago, but I'm a little more comfortable
specifying it explicitly.  Thus, given the topology of the bus in
question, I set the termination on the card to "on" (or, in one case
where the options were "off" or "auto," I left them at "auto").  Note
that the Antares card has resistor packs.

Now, I'll (finally) get to my symptoms....

frecnocpc6# chio params
/dev/ch0: 8 slots, 0 drive, 1 picker
/dev/ch0: current picker: 0
frecnocpc6#

That works OK.  Because of the errors I get below, I recompiled the
kernel, specifying the CAM debugging options and increasing the kernel
buffer from 10 pages to 40; here's what pops up on the (serial) console
when I did that:

(ch0:ahc0:0:6:0): entering cdgetccb
(ch0:ahc0:0:6:0): xpt_schedule
(ch0:ahc0:0:6:0): xpt_setup_ccb
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: 1a 8 1d 0 20 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): ahc_done - scb 9
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: 1a 8 1f 0 20 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): ahc_done - scb 2
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): entering chioctl
(ch0:ahc0:0:6:0): trying to do ioctl 0x40086306
(ch0:ahc0:0:6:0): entering chioctl
(ch0:ahc0:0:6:0): trying to do ioctl 0x40046304

Now, for an error condition:

frecnocpc6# chio status
chio: /dev/ch0: CHIOGSTATUS: Input/output error
frecnocpc6# 

and the corresponding console messages:

(ch0:ahc0:0:6:0): entering cdgetccb
(ch0:ahc0:0:6:0): xpt_schedule
(ch0:ahc0:0:6:0): xpt_setup_ccb
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: 1a 8 1d 0 20 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): ahc_done - scb 9
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: 1a 8 1f 0 20 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): ahc_done - scb 2
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): entering chioctl
(ch0:ahc0:0:6:0): trying to do ioctl 0x40086306
(ch0:ahc0:0:6:0): entering chioctl
(ch0:ahc0:0:6:0): trying to do ioctl 0x800c6308
(ch0:ahc0:0:6:0): entering cdgetccb
(ch0:ahc0:0:6:0): xpt_schedule
(ch0:ahc0:0:6:0): xpt_setup_ccb
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: b8 0 0 84 0 1 0 0 4 0 0 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): ahc_done - scb 9
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: b8 0 0 84 0 1 0 0 0 20 0 0 
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): data overrun detected in Data-in phase.  Tag == 0x2.
(ch0:ahc0:0:6:0): Have seen Data Phase.  Length = 32.  NumSGs = 1.
sg[0] - Addr 0x01367c180 : Length 32
(ch0:ahc0:0:6:0): ahc_done - scb 2
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): . CDB: b8 0 0 84 0 1 0 0 0 20 0 0 
(ch0:ahc0:0:6:0): xpt_setup_ccb
(ch0:ahc0:0:6:0): xpt_action
(ch0:ahc0:0:6:0): ahc_action
(ch0:ahc0:0:6:0): data overrun detected in Data-in phase.  Tag == 0x9.
(ch0:ahc0:0:6:0): Have seen Data Phase.  Length = 32.  NumSGs = 1.
sg[0] - Addr 0x01367c180 : Length 32
(ch0:ahc0:0:6:0): ahc_done - scb 9
(ch0:ahc0:0:6:0): xpt_done
(ch0:ahc0:0:6:0): camisr
(ch0:ahc0:0:6:0): xpt_setup_ccb
(ch0:ahc0:0:6:0): xpt_action


All of which I find rather perplexifying -- what can I do about it?

(The most recent previous experience I had was with an ADIC 7-slot DLT
autoloader & drive; no problems anything like this.  This one is made
by "Bason", and is an 8-slot AIT-3 autoloader & drive.)

The dmesg weighs in at about 56 KB, so I'm a little reluctant to post
it here, but I'll be happy to provide it privately (or put it up on
my Web server someplace), if that's called for.

Finally, please include me in replies; I'm not subscribed to -scsi at .

Thanks in advance,
david
-- 
David H. Wolfskill				david at catwhisker.org
If you want true virus-protection for your PC, install a non-Microsoft OS
on it.  Plausible candidates include FreeBSD, Linux, NetBSD, OpenBSD, and
Solaris (in alphabetical order).