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<someone> wrote:
Today Robert Elliott released 2 proposed changes to the
SAT INQUIRY command:
   - standard INQUIRY vendor, product revision strings changed
     to reference the SAT layer, not the actual ATA device


Unfortunately this first item has a flaw:
It requires SCSI software to have ATA-specific details to distinguish devices, which defeats most of the point of doing SCSI/ATA translation.


It makes it impossible to distinguish between ATA devices by looking at the SPC-standard INQUIRY data. SAT makes ATA appear like SCSI, so that SCSI software can be re-used. Adding ATA-specific details to SPC/SBC specs just defeats that purpose.

If software is gonna have ATA-specific details, then it might as well just be issuing ATA commands directly. And it is obviously bogus to expect existing SCSI software to know about a new ATA IDENTIFY DEVICE VPD page.


For the INQUIRY data, I think my solution is the best compromise: 'ATA' in the SCSI vendor string, and the first 16 bytes of the ATA model name in the SCSI product id string.


This solution indicates SCSI->ATA translation exists, but also allows SCSI software that knows nothing of ATA to easily distinguish between disk devices.

        Jeff




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