HP StorageWorks 12000, User Manual

Page: 130 / 266

4. Click Map LUNs in the task bar.
The Map LUNs window opens and displays the hosts with mapping enabled selected on the Host
LUN Mapping Mode window (
Figure 35 ).
Figure 35 Library Parameters – Map LUNs window
.
5. To allow a listed host to access the virtual library, enter a LUN value in the LUN box (such as 0,
1, 2, and so on).
The LUN value entered is assigned to the virtual library for that specific host. The default value
255 means the host does not have access.
6. When you are finished making changes, click Apply Settings .
7. Repeat these steps for the rest of the virtual libraries and tape drives configured on the VLS that
you want to make visible to the host.
CAUTION:
Each virtual device must be assigned a unique LUN number on the FC host port to which it is mapped.
If two virtual devices have the same LUN number on the same FC host port, the virtual device with
the lowest virtual device ID number assigned by the VLS is recognized as that LUN number by the
host's operating system. The other virtual device is ignored by the operating system.
Dual Port Virtual Devices
When creating a library robot LUN or tape drive LUNs, you can present the virtual devices to a pair
of host ports rather than just one port. Both ports must be on the same node. The
Port Mapping list
displays selections for each individual port plus possible port pairs (for example:
0
,
1
,
0&1
). The
benefit of dual port virtual devices is that they are still accessible when one path fails.
CAUTION:
Many operating systems and backup applications do not support more than one path to a tape library
device. Only use this feature if you are certain that it is supported.
When creating dual port virtual devices, the LUN numbering on both ports follows the conventions
for default LUN numbering (see “
Default LUN Numbering ” on page 121); however, if you use LUN
Configuration 130