U320 Drives Show up on Wrong Target ID?

Paul Berger phb.hfx at gmail.com
Sun Jun 5 09:28:18 CDT 2016


On 2016-06-05 6:25 AM, Jonathan Katz wrote:
> On Sun, Jun 5, 2016 at 7:26 AM,  <alexmcwhirter at triadic.us> wrote:
>> So in short i have six identical drives. Same manufacture, model, and
>> firmware. Three of them work fine, the other three also work fine but they
>> always show up as the wrong target.
> Is there a jumper on the drives that is overriding the address
> assigned by the enclosure? The whole point of SCA is that you don't
> use jumpers to assign the drive address, it just figures it out
> somehow. 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.


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