HP StorageWorks 9000 - Virtual Library System User Manual page 286

Symptom
286 Troubleshooting
Possible causes
There is a gap in the LUN number-
ing on the FC host port. Most oper-
ating systems will stop looking for
virtual devices on an FC host port
once a gap in the LUN numbering
is detected. For example, if LUN0,
LUN1, and LUN3 are mapped to
an FC host port, the operating sys-
tem will see LUN0 and LUN1.
When it does not find a LUN2, it
will assume there are no more
LUNs on the port and stop looking.
Solution
Use the VLS's LUN masking feature
to restrict the number of virtual
devices the host sees on the VLS FC
host ports, so it only sees the virtual
devices it needs to see. Then, use
the VLS's LUN mapping feature to
assign LUNs to the virtual devices
the host can see, such that the virtu-
al device LUN numbers include a
LUN0 and no gaps in the LUN
numbering. See LUN Masking
(v3.x) and LUN Mapping (v3.x)
instructions.
Remove the gap in the LUN number-
ing by editing the host's LUN map-
ping (see LUN Mapping (v3.x)), or
if a virtual device has been des-
troyed on the VLS, creating a gap
in the LUN numbering, restart the
VLS device emulations. The VLS
firmware will reassign LUNs to the
virtual devices as necessary to re-
move any gaps in the LUN number-
ing. See Restarting VLS Device
Emulations.
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