setboot(1M) in HP-UX 11i v3

Legacy Addressing
For backward compatibility, setboot still supports the use of legacy hardware paths to define the boot path. When
a legacy hardware path is given as input, setboot maps the legacy hardware path to the corresponding lunpath
hardware path and writes that lunpath hardware path to stable storage. Thus, the output shows the
lunpath hardware path and the associated persistent DSF, instead of the legacy hardware path initially
provided as input.
Important: This is a change from the behavior provided on HP-UX versions prior to 11i v3.
Please see Table 1 below for a summary of setboot behaviors when used with legacy addressing.
Table 1.
setboot Usage Input Type Description
setboot –a
/dev/disk/disk13
persistent DSF
setboot chooses any available lunpath hardware path to
the device with the persistent DSF /dev/disk/disk13
setboot –a
0/1/1/0.0x0.0x0
lunpath
hardware
path
setboot forces the use of the specified lunpath hardware
path 0/1/1/0.0x0.0x0 in stable storage
setboot –a
0/0/2/0.1.7.0
legacy
hardware
path
setboot converts the legacy hardware path 0/0/2/0.1.7.0 into
a lunpath hardware path and stores the lunpath
hardware path in stable storage
Multi-pathing and Failover
The mass storage stack in HPUX 11i v3 uses persistent DSFs to provide transparent multi-pathing. If a LUN has
multiple lunpaths, I/O requests are distributed across all available lunpaths to the LUN. If a lunpath fails, the non-
responsive lunpath is disabled, the active I/O request is switched, and the subsequent I/O requests will continue
on the available lunpaths.
If a boot path goes offline or is disabled, setboot is notified via an “offline health” event generated by the Event
Management System (EVM) for that boot path. Upon reception of this event, setboot tries to find an alternate
active lunpath to the LUN. If successful, setboot updates the stable storage with the hardware path for the alternate
active lunpath found.
Note: This mechanism is independent from the way the boot path was input to setboot. It applies for all types of
input, legacy hardware path, lunpath hardware path or persistent DSF.
If the LUN becomes completely inaccessible, for instance, if all lunpaths to the LUN are offline or disabled, setboot
attempts to switchover will fail and the boot path in stable storage will not be modified. If and when the LUN
comes back online, setboot is notified and tries to find an active lunpath to the LUN and writes its lunpath
hardware path to stable storage.
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