Date: Thu, 01 Mar 2007 17:17:36 -0800 From: "Marc D. Brooks" <marc@paralan.com> To: Baurzhan Ismagulov <ibr@radix50.net> Cc: aic7xxx@freebsd.org Subject: Re: Adaptec 2940UW with Fujitsu MAN3184M Message-ID: <45E77B30.2090505@paralan.com> In-Reply-To: <20070228233314.GA7348@radix50.net> References: <20070228204034.GA2379@radix50.net> <45E602B3.2020306@paralan.com> <20070228233314.GA7348@radix50.net>
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Hello Baurzhan,
I'll try to answer each of the sections below.
Baurzhan Ismagulov wrote:
>Hello Marc,
>
>Thanks for the prompt answer! Let's see what we can find out.
>
>On Wed, Feb 28, 2007 at 02:31:15PM -0800, Marc D. Brooks wrote:
>
>
>>The Adaptec 2940UW is Single Ended. With Single Ended, there are a
>>number of things to consider when trying to go Ultra. It is possible
>>that even though the 2940UW initially negotiates for Ultra, the domain
>>validation forces it to the slower rate due to issues seen with the
>>communications.
>>
>>
>
>Any way to see those at the Linux administrator level?
>
>
>
>
The type of SCSI the device and HBA supports is usually in the
specifications for the device and the HBA. Some BIOS implementations may
report the Single Ended, LVD or HVD bus type somewhere in its menus. For
Adaptec, in their model number they have the bus type encoded. 2940 =
Single Ended, 2944 = HVD, 29160 = LVD Ultra160, 29320 = LVD Ultra320.
For the Device you are using, I did a search for the data sheet for the
device and found out that it claimed to be Ultra160 device (It
automatically has to be LVD capable to do Ultra160).
>>The other thing to check is if the 2940UW BIOS has been forced to the
>>slower rate.
>>
>>
>
>The card is branded Siemens-Nixdorf, I don't see the usual Ctrl-A
>prompt. I've seen older SNI controllers, all settings were accessible
>from the main BIOS. So, I guess I can't check this.
>
>
>
This adds to the complexity of the problem. Adaptec works with many OEM
vendors in providing unique versions of firmware for their unique system
configurations. It is possible that the card you are using has
differences in its firmware from the generic Adaptec 2940UW such that
all bets are off in its operation. It may be possible to download the
generic firmware for that Controller to see if it then can operate as a
generic controller, though that part would be beyond my giving advice.
The card you have may be set to max out at Fast operation in the
firmware for that OEM card. The vendor may have the card factory set for
the type of drives that the system they were selling was using, which
may have not been Ultra speed capable.
>That said, when the driver is loaded, it states the USER setting of 40
>MB/s. Justin said that this is determined by EEPROM and /proc. I haven't
>set anything in /proc, so I guess we can rule out the BIOS setting
>limitation.
>
>
>
I agree with Justin's assessment. The OEM "Siemens" Factory Settings may
be causing the negotiations with the drive to not go at the Ultra speed,
or in performng domain validation, it had set to go slower in order to
operate without transmission errors. The 2940 physical card itself is
incapable of going any faster than Ultra, and it is limited to Single
Ended communications.
>The "when" part above is strange. Now I don't have the drive connected,
>aic7xxx is loaded, but I see neither kernel messages in log, nor
>/proc/aic7xxx. I'm running Debian sid's 2.4.18-4-k7. rmmod, modprobe
>don't help. At the last boot the module was also loaded, no messages,
>but rmmod, modprobe did help. The red LED named "DS1" is constantly lit.
>Should I throw the card away? Or could it be anything else (power
>supply???)?
>
>
>
>
Was the cable disconnected at the Adaptec, or at the drive package? If
at the drive package, the card may have been hung while trying to scan
the SCSI bus, since it would have lots of signal reflections from an
unterminated Single Ended bus. The hang could put it in a state of not
being able to respond until restarted, or its passed a hard reset. If
you intend on using that specifc OEM version 2940, unless the firmware
can be forced to generic, you may be limited to whatever speed you find
operates cleanly.
>>Also with Single Ended, the SCSI Cable Length can be critical.
>>Depending on a number of factors, going more than 2 meters may add to
>>the problem.
>>
>>
>
>1.2 m, four 68-pin connectors for drives, black box at the end saying
>"Foxconn" and "Ultra 320" (terminator?), the drive connected to the last
>entry before the terminator ("far" from the controller).
>
>
>
>
I do not have any direct experience with "Foxconn". It sounds like you
have a raid package or JBOD with a backplane. The terminator is
installed at the end of the backplane? With the drive close to the end.
That does not sound like it should be a problem, though there have been
problems with some backplanes in the past with running at Ultra speed
when using Single Ended SCSI.
>>The SCA-1 Adapter may also be adding to the problem unless it is known
>>to be able to work at the Ultra burst rate in Single Ended.
>>
>>
>
>Hmm, specifically SE? The adapter claims to be "Ultra4 320/m SCSI
>compliant". I'm not sure what "/m" means. MHz? It doesn't have any
>active components. One resistor goes from SCA-2 to the jumper named
>"LED". There are also SYN, DLY, MTR, ID3-0 jumpers, none set.
>
>
>
>
The "m" means Multi-mode, which means it can automatically switch down
from LVD to Single Ended if a Single Ended device and/or HBA is
connected to the bus. Thanks, there are also SCA adapters that are not
made for LVD, so I had to ask the question.
>>Also verify how you have the terminations. If these are the only two
>>devices, the 2940UW must have its terminations turned on (automatic
>>may be ok) and there should be a termination at the drive.
>>
>>
>
>The disk is the only device on the bus. If the black box is a
>terminator, then I guess I don't need termination on the drive. The
>drive is branded Sun and doesn't have any jumpers. I don't know whether
>one of the jumpers on the adapter is for termination; I assume none.
>
>At the other end, the controller has three connectors, two internal and
>one external. I guess it should be terminated. There are six jumper-like
>pins, four named J3, and two named J4.
>http://download.adaptec.com/pdfs/user_guides/p2940uw_ug.pdf doesn't
>mention anything about them, but says the termination can be set in BIOS
>to Auto, Enabled, or Disabled. Is there a way to check the setting?
>
>
>
>
The Adaptec can have termination set or unset through the BIOS menus,
but I do not know what it would take to do that or if its possible with
the Siemens OEM version card you have.
>>I believe the Fujitsu MAN3184M is Ultra160 Low Voltage Differential
>>(LVD), and capable of automatically going down to Single Ended
>>communications from LVD communications, like almost all LVD devices, but
>>its not being used to its full potential by doing so.
>>
>>
>
>Yes.
>
>
>
>
>>Changing to the 29160 controller which is Low Voltage Dfferential
>>(LVD) will help immensely in terms of being able to operate at a
>>faster burst rate and being able to reliably support longer SCSI cable
>>lengths.
>>
>>
>
>Do you think this will work properly with the adapter? I had stability
>problems with a similar adapter, AHA-2940UW, and the same drive
>(although that one was not claiming Ultra 320 compliancy).
>
>
The similar Adapte you mention is sill a Single Ended one. The stability
problems are most likely associated more with Ultra Speed Single Ended
SCSI than with the card itself. Ultra speed communications with Single
Ended devices were at the limit of the physical bus capabilities and a
lot of things could go wrong with it. Cabling, S.E. termination types,
etc... LVD is much more stable, especially up through Ultra160 transfer
rates. The only thing you really have to watch out for is improperly
made SCSI round cables. I would recommend that you swtch to an LVD
version (the 29160 should be fine) of a generic Adaptec controller,
since the SCA adapter, the Box that the adapter is in, and the Drive are
made to be able to support it.
>
>With kind regards,
>
>
I hope this helps a bit.
Best Regards,
Marc
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