HP StorageWorks 500 Modular Smart Array - Manual (Page 149)

Troubleshooting
D-16 HP StorageWorks Modular Smart Array 500 System User Guide
The expansion process is illustrated in the following figure, where the original array
(containing data) is shown with a dashed border, and the newly added drives are
shown unshaded (they contain no data). The array controller redistributes the original
logical drive over the enlarged array, using the same fault tolerance method. The
unused capacity on the new (enlarged) array can then be used to create an additional
logical drive, with a different fault tolerance setting if necessary. Alternatively, the
extra capacity can be used to increase the size of the original logical drive (capacity
extension).
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If you are expanding an array that has several logical drives, data is redistributed one
logical drive at a time. Newly created logical drives are not available until capacity
expansion is complete.