HP-UX System Administrator's Guide: Overview
/dev/rdsk/c0t6d0sdisk card instance 2 SCSI target 6 SCSI LUN 0 section 0 at
address 0/0/0/3/0.6.0 /dev/rdsk/c2t6d0
# /usr/sbin/lssf /dev/disk/*
esdisk section 0 at address 64000/0xfa00/0x0 /dev/disk/disk2 esdisk section 0 at
address 64000/0xfa00/0x1 /dev/disk/disk3
The /usr/sbin/ioscan command will also show you hardware path information
about the devices on your system:
Here is the legacy view of the disk drives on a system:
# /usr/sbin/ioscan -C disk
H/W Path Class Description
=====================================================
0/0/0/2/0.6.0 disk HP 36.4GMAN3367MC
0/0/0/3/0.6.0 disk HP 36.4GMAN3367MC
Here is the agile view of the same disk drives (showing the virtual LUN hardware
paths rather than the actual hardware paths):
# /usr/sbin/ioscan -N -C disk
H/W Path Class Description
=====================================================
64000/0xfa00/0x2 disk HP 36.4GMAN3367MC
64000/0xfa00/0x3 disk HP 36.4GMAN3367MC
Legacy versus Agile Device Addressing
Beginning with HP-UX 11i version 3, mass storage devices are referenced by device
instances rather than by the hardware paths to the devices. This has many benefits over
the previous addressing scheme which associated a given device special file with the
hardware path to a device. Device hardware addressing for mass storage devices is
now fluid, automatic, and transparent. This has many benefits.
NOTE: For compatibility with previous HP-UX releases, the previous (legacy) device
addressing scheme for mass storage devices is still supported under HP-UX 11i version
3; therefore scripts, configurations, and other uses of device special files you have
previously created will continue to work.
For transition purposes, you can use both legacy device addressing (using legacy device
special files) and agile device addressing (using persistent device special files)
simultaneously, but to take advantage of the many benefits of agile device addressing,
and for future compatibility reasons, you should transition to using persistent device
special files going forward once all of the underlying file systems and technologies that
you use can support them.
Greater Configuration Stability
Agile device addressing allows for hardware paths to change between system boots
(for example, if a LUN is moved from one HBA to another while a server is shutdown)
and for SAN configurations to change without requiring changes to device special files
62 Major Components of HP-UX