HP StorageWorks XP Remote Web Console Software - Manual (Page 100)

100 Using XP12000 disk arrays with EVA GL disk arrays attached as subordinated external storage disk arrays
optimization algorithm the ACU uses can be compensated for by specifying a size of 40963 MB, which
results in the correct size of 40960 MB (40 GB).
Figure 59 Defining MSA LUs with ACU
Selective Storage Presentation
You must institute LUN security on MSAs using the ACU Selective Storage Presentation (SSP) feature
( Figure 60 ). Use SSP to limit access to individual MSA LUs (in this case, logical drives 1 and 2) by selected
host (or XP10000/XP12000) HBA world wide names. When using SSP, set the operating system mode
corresponding to the XP10000/XP12000 array port WWN to TRU64. For more information about
configuring the MSA using the ACU, see the ACU Online User Guide.
Figure 60 Configuring SSP with ACU
Recommendations
Performance considerations for using EVAs as external storage
Unlike the MSA family of disk arrays, an EVA can be configured to perform I/O operations with both its
controllers on separate EVA LUs simultaneously (Active/Passive capability). Therefore, it is possible to
realize more/better performance from an EVA in an external storage role by creating multiple connections
from the XP12000 external port to a given EVA controller (remembering that the EVA GL models have two
ports per controller) than a similar configuration with an MSA (only one port per controller). In spite of this,