HP XP External Storage Software - Manual (Page 193)

Defining MSA array objects
Use the Array Configuration Utility (ACU) to define at least one internal MSA array object (for instance,
“A”) when first setting up the array. After defining an array object, specify LUs within that array object.
Figure 75 Defining MSA array objects with the ACU
Calculating MSA LU size and defining LUs
The ACU used for configuring the MSA uses an optimization algorithm to calculate the user size of
a new LU given a user-specified size in MB (
Figure 76 ). Because you cannot bypass or disable the
optimization algorithm, you must compensate for this optimization so that MSA LUs are created at
the correct size. When requesting a new LU through the ACU, make the request 2 to 3 MB larger
than needed for presentation to the XP12000/XP10000/SVS200. For example, suppose you want
to create a 40 GB (40960 MB) LU on the MSA for use as XP12000/XP10000/SVS200 external
storage. If you request only the exact size needed, the ACU optimizes the LU to a size of 40959 MB,
which is 1 MB smaller than needed. In this case, the 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).
External Storage XP user guide for the XP12000, XP10000, SVS200 193