HP XP P9500 Storage - Manual (Page 27)

LUN Expansion
External volumes can be used in a LUSE volume with the following restrictions:
•
An internal volume in the local storage system and a mapped external volume cannot be
combined to form a LUSE volume.
•
Only LDEVs from the same external storage system can be used in a LUSE volume. Do not
combine LDEVs of multiple external storage systems to create a LUSE volume, otherwise the
following occurs:
◦ When one external volumes is lower performing than others, it affects the performance
of the LUSE volume.
◦ If an external volume that is part of a LUSE volume is blocked, the data reliability of the
LUSE volume deteriorates because the LUSE volume has both accessible areas and
inaccessible areas from a host.
◦ If an external volume in a LUSE volume is disconnected or reconnected, all external
volumes in the LUSE volume must be disconnected or reconnected at the same time.
•
All external volumes in a LUSE volume must use the same Cache Mode setting. For more
information about this setting, see
“Cache use and external storage performance” (page 14) .
Performance Monitor and Auto LUN V2
Performance Monitor can be used to display monitoring information for mapped external volumes.
Mapped volumes can also be used for Auto LUN. The following figure shows an example of an
external volume used as the source volume in a Auto LUN operation. Existing data in the external
volume is migrated manually to the local system’s native internal volume.
Procedure 1 To use an external volume for volume migration
1. Map the external volume. If using the external volume as a source volume, set Emulation Type
to OPEN-V. This is required to access existing data in an external volume from the local system
(for volume migration as well as replication).
2. Ensure that both volumes have the same capacity. Adjust the capacity as needed using the
LUSE and the Virtual LVI/Virtual LUN functions.
3. Set the source and target volumes.
4. Migrate the data using Auto LUN.
LUN Expansion 27