User Manual

SCSI Commands Reference Manual, Rev. J 490
www.seagate.com Parameters for direct access devices
5.4.11 Device Identification VPD page (83h)
The Device Identification VPD page (see table ) provides the means to retrieve zero or more identification descriptors applying to
the logical unit. Logical units may have more than one identification descriptor (e.g., if several types or associations of identifier
are supported). Device identifiers consist of one or more of the following:
• Logical unit names;
• SCSI target port identifiers;
• SCSI target port names;
• SCSI target device names;
• Relative target port identifiers;
• SCSI target port group number; or
• Logical unit group number.
Identification descriptors shall be assigned to the peripheral device (e.g., a disk drive) and not to the currently mounted media, in
the case of removable media devices. Operating systems are expected to use the identification descriptors during system
configuration activities to determine whether alternate paths exist for the same peripheral device.
PERIPHERAL QUALIFIER and the PERIPHERAL DEVICE fields
The PERIPHERAL QUALIFIER field and the PERIPHERAL DEVICE TYPE field are defined in standard INQUIRY data (see 3.6.2).
PAGE CODE field
The PAGE CODE field shall be set to the value defined in table .
PAGE LENGTH field
The PAGE LENGTH field specifies the length of the following VPD page data. The relationship between the PAGE LENGTH field and the CDB
ALLOCATION LENGTH field is defined in
2.2.6.
Table 459 Device Identification VPD page
Bit
Byte
7 6 5 4 3 2 1 0
0 PERIPHERAL QUALIFIER PERIPHERAL DEVICE TYPE
1 PAGE CODE (83h)
2 MSB
PAGE LENGTH (n-3)
3 LSB
Identification descriptor list
4
Identification Descriptor (first) (see table 460)
. . .
. . .
Identification Descriptor (last) (see table 460)
n