HP StorageWorks External Storage XP user guide (T1706-96006, June 2006)

External Storage XP user guide 75
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” on page 20).
HP recommends that you set cache mode to Disable.
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” on page 20)
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
Displays the Select Paths pane (Figure 43). Use the Select Paths pane to select paths as candidates for
primary and alternate paths and select paths that cannot be set to primary and alternate paths. By
default, all paths with a confirmed connection status of normal are set as candidates for primary and
alternate paths. However, to set a specific path as the alternate path, use the Select Paths pane to
specify candidates for alternate paths. Alternate paths are automatically set from the candidates, as
many as the number set in Alternate Path.
CAUTION: If you do not set alternate paths on the Select Paths pane, alternate paths are
automatically set according to the WWN selected in the Device tree on the LU Operation pane
when you started the Add LU operation.
• Clear button
Resets all the external LU’s attributes.
• CU list
CU number of the local array to which you want to map the external LU. Select the CU number from the
list. When the Limited check box is selected, the selection range is limited to the CU belonging to the
SLPR displayed in CLPR.
• Linear button
Maps all external LUs listed in the CU:LDEV list at one time. When you click Linear and then select an
internal LDEV on the LDEV map, External Storage XP automatically selects from the LDEV map the same