Phy; Sas Domain; Scsi Domain; Scsi Initiator - HP 381513-B21 - Smart Array P800 Controller RAID Technology Brief

phy

phy is a generic electronics term referring to an electronic integrated circuit or a functional block of a
circuit that encodes and decodes transmissions between a pure digital domain (on-off) and a
modulation in the analog domain. A 'SAS phy' is a combination of the physical layer, phy layer and
link layer functions. A minimum of two phys (one at the initiator, the other at the target) is required to
complete a SAS physical connection pathway, as shown in Figure A-1.
Figure A-1 phys are required to complete a SAS physical connection
.
device
device
Port
Port
port
port
Phy
Phy
phy
phy
SAS phy SAS phy
link phy physical physical phy link
layer layer layer layer layer layer

SAS domain

A SAS domain consists of one or more SAS devices and expander devices and can be contained
within a SCSI domain

SCSI domain

A SCSI domain contains a service delivery subsystem and one or more SCSI devices. Additionally,
this domain contains a set of SCSI initiator ports and target ports that can communicate with each
other when interconnected by a service delivery subsystem.

SCSI initiator

The SCSI initiator is the host-side endpoint of a SCSI session. SCSI initiators request data transfers
from SCSI targets. An HBA is an example of a SCSI initiator.

SCSI initiator port

A SCSI initiator port acts as the connection between application clients and the service delivery
subsystem through which requests and responses are routed. In all cases when this term is used it
refers to an initiator port or a SCSI target/initiator port operating as a SCSI initiator port.

SCSI target port

A SCSI target port contains a task router. It acts as the connection between device servers and task
managers and the service delivery subsystem through which requests and responses are routed.
When this term is used it refers to a SCSI target port or a SCSI target/initiator port operating as a
SCSI target port.
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