HP StorageWorks XP Remote Web Console Software - Manual (Page 20)

If a volume is used for multiple purposes, only the capacity of the volume itself is added to the total volume
capacity. There is no need to multiply the capacity of this volume by the number of purposes it is used for.
(For example, if you specify a volume as an S-VOL, and use it as a reserved volume as well by setting its
reserve attribute (see section “ Set Reserve Attribute Operation ” on page 25 for details), only the capacity
of the volume itself is added to the total volume capacity and there is no need for it to be doubled.)
FlashCopyMirror S-VOLs and T-VOLs are counted not only as FlashCopy Mirror volumes but also as Siz
volumes. The total capacity of FlashCopy Mirror volumes that you can use cannot exceed the maximum
volume capacity licensed to you under the terms of your Compatible Mirroring for FlashCopy agreement.
The following figures illustrate how to calculate the total capacity of volumes that you will use with Siz.
For these examples, the capacity of each volume is assumed to be 1. The colored volume or volumes
represent the volumes that are used. The following is an example of one reserved volume and one
unreserved volume. In this example, the total capacity of the Siz volume in use is 1.
Reserved Not reserved
Figure 2 Total Capacity of Siz Volumes (Example 1)
The following figure is an example of two Siz pairs. In this example, the total capacity of Siz volumes
in use is 3.
S-VOL T-VOL
(Reserved)
Legend
: SIz pair
T-VOL
(Reserved)
Figure 3 Total Capacity of Siz Volumes (Example 2)
The following figure is an example of Siz pairs and FlashCopyMirror pairs. In this example, the total
capacity of Siz volumes in use is 5, and the total capacity of XP for FlashCopy Mirroring Software
(FlashCopy Mirror) volumes in use is 3.
20 Overview of Hitachi ShadowImage for z/OS Operations