Using Serviceguard Extension for RAC, 5th Edition, June 2007

Serviceguard Configuration for Oracle 9i RAC
About Device Special Files
Chapter 3 141
About Device Special Files
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 the pre-11i v3
nomenclature. 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. It is possible, though not a best practice, to have
legacy DSFs on some nodes and agile addressing on others; this allows
you to migrate the names on different nodes at different times, if
necessary.