HP StorageWorks XP Remote Web Console Software - Manual (Page 40)

Figure 11 Example of external LU with 2 TB or less
.
• If you map an external LU that is equal to or greater than 575.98 GB with an OPEN emulation
type other than OPEN-V, you can access data stored in the field up to 575.98 GB. You cannot
access data stored in the field over 575.98 GB.
However, for emulation types with a small base capacity, some of the field of 575.98 GB might
not be available. For more information, see
Appendix B .
• If you map an external LU that is equal to or greater than 575.98 GB with a 3380 mainframe
emulation type, you can access data stored in the field up to 575.98 GB. You cannot access data
stored in the field over 575.98 GB.
However, for emulation types with a small base capacity, some of the field of 575.98 GB might
not be available. For more information, see
Appendix B .
• If you map an external LU that is equal to or greater than 695.98 GB with a 3390 mainframe
emulation type, you can access data stored in the field up to 695.98 GB. You cannot access data
stored in the field over 695.98 GB.
However, for emulation types with a small base capacity, some of the field of 695.98 GB might
not be available. For more information, see
Appendix B .
• If you plan to use the mapped external LU from the mainframe OS (volume is mapped with a
3380-x or 3390-x mainframe emulation type), you must select an external LU that consists of one
LDEV or you must first adjust the capacity of the external LU to be mapped. If multiple LDEVs exist
in one external LU and if numerous I/Os are made to these LDEVs, the read and write commands
might time-out. When the commands time-out, the SIM (21D2xx) is reported.
• When mapping an external LU as internal LDEVs with emulation types other than OPEN-V, the
number of volumes and the volume capacity of the mapped internal LDEVs depends on the original
external LU's capacity and each emulation type's normal size. When mapping an external LU
using emulation types other than OPEN-V, an XP array management information area is required
in the mapped LU. This means that the capacity available after mapping is slightly smaller than
the actual external LU capacity. Available capacity decreases by the size of the XP array manage-
ment information area, and all prior data must be considered lost. For more information, see the
HP StorageWorks Flex Copy XP user guide.
Figure 12 shows an example where the external LU's original capacity is larger than (or a multiple
of) the normal size of the local array's emulation type (OPEN-3 in this example). Therefore, in this
example, the local array can realize two fully-sized OPEN-3 LDEVs, with some space (insufficient
to create a full OPEN-3) left over.
Preparing for XP External Storage operations 40