LTO-3 / scsi woes

[Scott Long]

See my responses inline.....


On Jan 15, 2008, at 1:12 PM, Robin Blanchard wrote:

> By "bypass" I mean I plugged the LTO drive directly to the controller
> rather than in-line through the library. I am only using sym0 (the LVD
> channel).
>
> These are the devices in question:
> <QUALSTAR RLS-8204-20 006D>        at scbus0 target 0 lun 0  
> (ch0,pass0)
> <IBM ULTRIUM-TD3 73P5>             at scbus0 target 1 lun 0  
> (sa0,pass1)
>

I'm trying to reconstruct the conversation here.  Are you saying that  
you've tried LSI, Adaptec, and Symbios controllers, and they've all  
failed with your drive?

>
> Thanks for your help....
>
>> -----Original Message-----
>> From: Bob Hetzel [mailto:beh at case.edu]
>> Sent: Tuesday, January 15, 2008 2:56 PM
>> To: Robin Blanchard
>> Subject: Re: [Bacula-users] LTO-3 / scsi woes
>>
>> Robin,
>>
>> The Freebsd log says the controller is operating at Fast-80... that
>> doesn't sound good.  I also noted that it's a dual channel with the
>> other channel operating SE (single ended which is "high voltage" scsi
>> as
>> opposed to LVD or low voltage.
>>

SE does not mean "high voltage scsi", HVD does.  A bus can operate at  
either LVD, HVD, or SE.  LVD and SE are compatible in the sense that  
LVD and SE peripherals can interoperate with an LVD or SE controller,  
with the only caveat being that the presence of any SE devices will  
bring everything down to SE speeds (20MHz bus).  HVD can not  
interoperate with these, and any attempt to do so will likely cause  
nothing short of a _fire_.

Also, I don't understand your comment about the controller reporting  
that it's operating in Fast-80 mode.

>> Also, when you say "bypassed" can you clarify?
>>
>>    Bob
>>
>> Robin Blanchard wrote:
>>> Bob,
>>>
>>> Thanks for the length reply and suggestions. I've swapped
> terminators
>>> (I've got a U160 and a U320, both with indicator lights -- both
>> indicate
>>> 'green'), as well as cables, cards, and even the drive itself (we
>> have
>>> two of the same library, each with a single drive in each). The
>>> "closest" I've come thus far is to bypass the library/exchanger, and
>>> connect only the LTO-3 drive; but having to set the speed to 20
> MB/s.
>>> Using an adaptec card, I get absolutely nowhere at all, hence the
>>> current use of the LSI card (which, yes, is LVD/SE). I just
> installed
>>> FBSD (as opposed to RHEL5) to see if I could glean anything else
>> useful.
>>> The attached dmesg is FBSD 6.2-STABLE with the LSI (sym) card, and
>> the
>>> library/drive both set in the BIOS to defaults/auto.
>>>
>>>
>>> With an adaptec 2940U2W, I get nothing but garbage:
>>>

This means that the device responded to a selection for an INQUIRY  
command (the first command that is issued to each possible on a bus),  
but then something went wrong to make the driver think that the  
command didn't progress to completion.  It could be something funky  
with the bus, termination, controller, or driver, but the suggestion  
in the error message that interrupts are working could well be a hint  
here.  First of all, are there any other devices on the bus that do  
work?  What kind of system is this, and what version of FreeBSD are  
you using?  Since it sounds like you've tried multiple SCSI cards,  
have you been putting all of them into the same PCI slot, or have you  
tried different PCI slots?  Have you tried any of the published tricks  
for working around interrupt problems (disabling ACPI, disabling APIC,  
etc)?

Scott