HP Serviceguard Version A.11.19 Release Notes, October 2009

Features First Introduced Before Serviceguard A.11.18
About Device Special Files (DSFs)
HP-UX releases up to and including 11i v2 use a naming convention for device files
that encodes their hardware path. For example, a device file named /dev/dsk/
c3t15d0 would indicate SCSI controller instance 3, SCSI target 15, and SCSI LUN 0.
HP-UX 11i v3 introduces a new nomenclature for device files, known as agile addressing
(sometimes also called persistent LUN binding).
Under the agile addressing convention, the hardware path name is no longer encoded
in a storage device’s name; instead, each device file name reflects a unique instance
number, for example /dev/[r]disk/disk3, that does not need to change when the
hardware path does.
Agile addressing is the default on new 11i v3 installations, but the I/O subsystem still
recognizes pre-11i v3 device files, which as of 11i v3 are referred to as legacy device
files. Device files using the new nomenclature are called persistent device files,
When you upgrade to HP-UX 11i v3, a set of new, persistent device files is created, but
the existing, legacy device files are left intact and by default will continue to be used
by HP-UX and Serviceguard.
This means that you are not required to migrate to agile addressing when you upgrade
to 11i v3, though you should seriously consider its advantages (see the white paper
The Next Generation Mass Storage Stack under Network and Systems Management
-> Storage Area Management at docs.hp.com). Migration involves modifying
system and application configuration files and scripts to use persistent device files and
in some cases new commands and options; the process is described in the white papers
Migrating from HP-UX 11i v2 to HP-UX 11i v3 and LVM Migration from Legacy to Agile
Naming Model HP-UX 11i v3 at docs.hp.com.
If you cold-install HP-UX 11i v3, sets of both legacy and persistent device files are
automatically created. In this case, by default the installation process will configure
system devices such as the boot, root, swap, and dump devices to use persistent device
files. This means that system configuration files such as/etc/fstab and /etc/lvmtab
Features Introduced Before A.11.19 47