U320 Drives Show up on Wrong Target ID?

alexmcwhirter at triadic.us alexmcwhirter at triadic.us
Sun Jun 5 13:50:04 CDT 2016

On 2016-06-05 10:28, Paul Berger wrote:
> It sounds like the SCA isn't being allowed to do its thing.
> The SCA connectors has pins on it for setting the drive address, so
> the the disk backplane slot that the drive is plugged into sets the
> drive address.  These drives normally have jumper positions on them to
> set addresses as well, however the normal case is that the actual
> address is the backplane set address ORed with what is set in the
> jumpers.  For instance if the drive has a jumper for address 2 set,
> and you plug it into the address 0 slot it will respond to address 2,
> but if you plug it into the address 1 slot it will respond to address
> 3, but when plugged into slot with address 2 it will correctly respond
> to 2.  The OP claims that these
> drives respond to the same address no matter where they are plugged,
> which does not seem possible on any SCA drive I have ever seen.
> If the drives happen to have 50 or 68 pin connectors that are mounted
> on a carrier with a connector that plugs into a backplane that sets an
> address, in this case this is normally done with a small cable that
> connects the auxiliary connector on the drive to the appropriate pins
> on the carrier, in that case if this cable is disconnected and address
> jumpers are installed on the drive, I could see the OP's situation
> occurring.
> I have no experience with Sun disk enclosures so I don't know what
> sort of drives or drive carriers they use in their enclosures so I
> cannot say for sure what may be going wrong.
> Paul.

So the D1000 is mostly a dumb box. It only has functions to set 
addresses and power on / off the drives. It uses standard SCA scsi 
drives, nothing fancy. Anyways, yes one of the drives shows up as target 
two no matter what slot it's in. If there is another drive in slot two 
the target id's will conflict.

There are no pins on these drives, and the exhibit the same behavior in 
other machines. I just find it weird, hopefully the other three drives 
don't start doing the same thing.

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