Generally there are bus drivers for various kinds of buses. One such example is a PCI bus driver. The bus driver creates a PDO (Physical device objects) for every device on that bus.
Hence if i have a SAS Host based adapter (storage controller ) on the PCI bus, there will be corresponding PDO for that as well.
Now when there are SAS disks connected to the HBA, typically the disks will be on a SCSI bus. My question is whether there will be a PDO for each of these SAS disks as well? If yes, who will create those PDO? If not, why not?