HP-UX 11i v3 Mass Storage Device Naming
The Agile Addressing Hardware Path Format
The agile addressing scheme defines two new sets of hardware paths for each device:
• The LUN hardware path: is a virtualized path, which represents the LUN independently of
any of its I/O paths.
• A set of lunpath hardware paths: each represents a specific I/O path to the LUN and maps
to a single legacy hardware path. The format of the lunpath hardware path is different from
the legacy hardware path and depends on the SCSI transport.
LUN hardware path format
The virtualized LUN hardware path is built using the following elements:
• The root node of all virtual devices: by convention this has the constant address 64000.
Virtual devices in the context of the I/O tree are devices for which the hardware path does
not represent any physical location of the device.
• The virtual bus address under which all LUN nodes are attached: by convention this has the
constant address 0xfa00.
•
A
virtual LUN identifier corresponding to the hexadecimal representation of the default minor
number assigned to the device in the agile view.
So the hardware path of a LUN will always have the following format: 64000/0xfa00/0xh, where h
is the hexadecimal representation of the default minor number assigned to the device.
The following ioscan output shows examples of LUN hardware paths and persistent DSFs for disk
devices.
# ioscan -kfNnC disk
Class I H/W Path Driver S/W State H/W Type Description
===================================================================
disk 15 64000/0xfa00/0x0 esdisk CLAIMED DEVICE HP 36.4GST336706LC
/dev/disk/disk15 /dev/rdisk/disk15
/dev/disk/disk15_p1 /dev/rdisk/disk15_p1
/dev/disk/disk15_p2 /dev/rdisk/disk15_p2
/dev/disk/disk15_p3 /dev/rdisk/disk15_p3
disk 16 64000/0xfa00/0x1 esdisk CLAIMED DEVICE HP 36.4GST336706LC
/dev/disk/disk16 /dev/rdisk/disk16
/dev/disk/disk16_p1 /dev/rdisk/disk16_p1
/dev/disk/disk16_p2 /dev/rdisk/disk16_p2
/dev/disk/disk16_p3 /dev/rdisk/disk16_p3
disk 17 64000/0xfa00/0x2 esdisk CLAIMED DEVICE TEAC DV-28E-B
/dev/disk/disk17 /dev/rdisk/disk17
disk 18 64000/0xfa00/0x3 esdisk CLAIMED DEVICE SEAGATE ST39103FC
/dev/disk/disk18 /dev/rdisk/disk18
Lunpath hardware path format
The format of the lunpath hardware path is as follows:
• <HBA hw path>.<target port WWN or port id>.<SCSI-3 LUNid>
Where:
• HBA hw path: legacy HBA hardware path (example: 0/3/1/0).
• target port WWN or port id: hexadecimal representation of the target port Worldwide name
(WWN), or the target port identifier if the SCSI transport does not support WWN (example:
0x21000020370fe8c8 for WWN, and 0x0 for port id).
• SCSI-3 LUNid: hexadecimal representation of the SCSI-3 64 bit LUN identifier.
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