FC questions, specifically isp(4), sa(4) and mt(1)

[Harry Schmalzbauer]

 Dear scsi gurus,

I'm asking for help regarding FibreChannel support in FreeBSD. I thought
questions@ wasn't really adequate, please tell me if scsi@ isn't either.

First I'd like to ask if there's alreday any translation (documentation
newer than isp(4)) between dev.isp.N.topo|loopstate|etc. and
hint.isp.N.topology etc.
The only matching component I found in man 4 isp was "role". Especially
hint.isp.0.fullduplex seems weird to me...
I will have a look into the driver to see if I can answer some questions
myself, but any links to more info are welcome.

My specific problem is that mt(1) seem to crash my LTO3 drive.
I'm quiet new to FC, but I think using a QLE2532 in N_port and initiator
role togehter with the FC drive shouldn't need any more
understanding/tuning than doing the same with LSI2008 and an SAS drive,
besides the different wiring ;-)

At first, it looks like I was right with that assumption, since
camcontrol(8) behaves as usual:

    'camcontrol devl'
<HP Ultrium 3-SCSI L63S>           at scbus8 target 0 lun 0 (sa0,pass3)
    'camcontrol inq sa0'
pass3: <HP Ultrium 3-SCSI L63S> Removable Sequential Access SCSI-3 device
pass3: Serial Number HUE07491PW
pass3: 200.000MB/s transfers, Command Queueing Enabled
    'camcontrol load sa0 && camcontrol tur sa0'
Unit started successfully, Media loaded
Unit is ready
...

But as soon as I issue a 'mt status', the drive seems to crash and I get
the following kernel messages:
isp0: Chan 0 LIP destroyed 1 active commands
isp0: Chan 0 LIP destroyed 1 active commands
(sa0:isp0:0:0:0): unable to rewind after test read
mt: /dev/nsa0: Input/output error
or if port is forced to N_ instead L_:
sa0: <HP Ultrium 3-SCSI L63S> s/n HUE07491PW detached
(sa0:isp1:0:0:0): unable to rewind after test read
(sa0:isp1:0:0:0): Periph destroyed
mt: /dev/nsa0: Input/output error

Like mentioned, the drive seems to crash/reboot according to the LEDs.

Am I wrong that mt(1) shouldn't make a difference if it's a P-SCSI, SAS
or FC drive?

Is there a document where some cmd/smpcmd are collected which I could
use to start narrowing down the source of the error?

Thanks,

-harry