<div>
AFAIK, Yes there will be for each physical disk. If you use RAID then the output of the raid will be presented to the o/s as the physical disk.
</div>


AFAIK, Yes there will be for each physical disk. If you use RAID then the output of the raid will be presented to the o/s as the physical disk.

<div>
which bus driver will be &nbsp;responsible for creating the PDOs for scsi disks? I dont think it is the PCI bus driver.
</div>


which bus driver will be  responsible for creating the PDOs for scsi disks? I dont think it is the PCI bus driver.

<div>
<div class="content wysiwyg-content">
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 &nbsp;objects) for every device on that bus.<br />
Hence if i have a SAS Host based adapter (storage controller ) on the PCI bus, there will be corresponding PDO for that as well.<br />
<br />
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? &nbsp;If not, why not?
</div>
</div>


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?

Will there be Physical device objects (PDOs) for SCSI disks connected to a SCSI HBA?

The Microsoft Legacy Operating System topic includes legacy versions of Microsoft operating systems prior to Windows 2000: All versions of MS-DOS and other versions developed for specific manufacturers and Windows 3/3.1, Windows 95 and Windows 98, plus any other Windows-related versions, and Windows Mobile.

Microsoft Legacy OS

Servers are computing devices that are similar to desktop computers in that they have the same basic components, but are significantly different in size, configuration and purpose. Servers are usually accessed over a network, and many run unattended, without a computer monitor, input device, audio hardware or USB interfaces. Many servers do not have a graphical user interface (GUI), and are configured and managed remotely. Servers typically include hardware redundancy such as dual power supplies, RAID disk systems, and ECC memory, along with extensive pre-boot memory testing and verification. Critical components might be hot swappable, and to guard against overheating, servers might have more powerful fans or use water cooling.

Server Hardware

Storage devices include any device used for storing and retrieving digital information. Hard disk drives (HDDs) use one or more rigid ("hard") rapidly rotating disks (platters) coated with magnetic material. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order and not only sequentially. The primary competing technology for secondary storage is flash memory in the form of solid-state drives (SSDs), but HDDs remain the dominant medium for secondary storage due to advantages in price per bit and per-device recording capacity. CD-RW (Compact Disc-ReWritable) is a digital optical disc storage format that allows information to be stored outside the mechanical HDD.