HP XP External Storage Software - Manual (Page 90)

CAUTION:
To use the mapped external LU for the software products other than Flex Copy XP (such as Cache
LUN XP, Auto LUN XP, Continuous Access XP, Continuous Access XP Journal Business Copy XP,
or Snapshot XP), set
IO Suppression mode to Disable.
CAUTION:
To set IO Suppression mode to Disable, External Storage XP must be installed.
CAUTION:
To set IO Suppression mode to Enable, Flex Copy must be installed.
• Cache Mode
Specifies if the write I/O from the host is propagated synchronously or asynchronously to the
external storage device (see
External LU attributes set by mapping ).
HP recommends that you set cache mode to Disable.
Data that is not written by the host (for example, data written by XP Business Copy) is
asynchronously destaged to the external subsystem regardless of the Cache Mode setting.
NOTE:
• If you set the IO Suppression mode to Enable, Cache Mode becomes Disable.
• If you select Disable, Cache LUN XP's bind mode cannot be set.
• If you specified a mainframe-system emulation type for the mapped LU, host I/O is always
propagated asynchronously to the external LU regardless of the Cache Mode setting.
• Alternate Path
Number of alternate paths automatically set when mapped. Value can be from 0 to 7. Default is
1.
CAUTION:
If the specified number of alternate paths cannot be set, an error appears in the Preset list.
• CLPR (see External LU attributes set by mapping )
When cache memory is partitioned using XP Disk/Cache Partition, you can select the CLPR used
to access the mapped volume from the list. The SLPR number that the selected CLPR belongs to
appears on the right of the list. However, if you select a mainframe emulation type in Emulation
Type, you can only select CLPRs belonging to SLPR number 0. The Limited check box appears on
the right of the SLPR number. To display only CUs defined for the selected SLPR, select the Limited
check box. To display all CUs, regardless of the SLPR, clear the check box. By default, the Limited
check box is selected.
• Select Paths button
Configuring external LUs 90