HP StorageWorks User Manual page 69

Number of LDEVs that can be mapped based on the capacity supported by the emulation type
specified in the Emulation Type box. Select the number of LDEVs you want to map from the Create
LDEVs list. The default is Full. When Create LDEVs is Full, the maximum number of LDEVs that can be
created based on the capacity supported by the specified emulation type are mapped. The total
number of LDEVs being mapped appears at Total.
• IO Suppression
When you specify the OPEN-V emulation type, you can specify the mapped LU's IO Suppression mode
(see "External LU attributes set by
If you suppress I/O operations from hosts (by way of the XP12000/XP10000) to the mapped external
LU or use the mapped external LU for a Flex Copy XP pair, select Enable.
If you do not suppress I/O from hosts to the mapped external LU, select Disable (for example, for
External Storage XP).
When you set the emulation type to something other than OPEN-V, I/O Suppression mode is
automatically set to Disable.
When the external LU to be mapped has the VMA setting, IO Suppression mode is automatically set to
Disable.
CAUTION: To use the mapped external LU for products other than Flex Copy XP (such as Cache
LUN XP, Auto LUN XP, Continuous Access XP, Continuous Access XP Journal, and Business Copy
XP), set IO Suppression mode to Disable.
CAUTION: To set I/O Suppression mode to Disable, External Storage XP must be installed.
CAUTION: To set IO Suppression mode to Enable, Flex Copy XP must be installed.
• Cache Mode
Specifies if the write I/O from the host is propagated synchronously or asynchronously to the external
storage device ("External LU attributes set by
To propagate write I/Os from the host to the external disk array asynchronously, select Enable.
To propagate write I/Os from the host to the external disk array synchronously, select Disable.
If you set IO Suppression mode to Enable, Cache Mode is automatically set to Disable.
CAUTION: If you set Disable, Cache LUN XP's bind mode cannot be set.
CAUTION: If you set the mapped LU to a mainframe-system emulation type, the host I/O is always
propagated asynchronously to the external LU, regardless of the Cache Mode setting.
• Start CU:LDEV
First CU:LDEV number in the series of mapped destination internal XP LDEVs. The default is "- : -".
Interval also appears. The default is 0.
To have External Storage XP select the first CU:LDEV number for the mapped internal XP LDEV, leave
the default ("- : -"). External Storage XP searches for an available CU:LDEV number starting with
00:00, and selects the first one it finds.
To specify the first CU:LDEV number and interval, click Select LDEV. The Select LDEV window
(Figure 38) appears.
• Alternate Path
Number of alternate paths automatically set when mapped. Values can be from 0 to 7. Default is 1.
mapping" on page 20).
mapping" on page 20).
External Storage XP user guide 69