HP StorageWorks XP Remote Web Console Software User Manual

Page 80

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IO Suppression

Mapped external LU's IO Suppression mode (for OPEN-V emulation only) (see

External LU

attributes set by mapping

).

To suppress I/O operations from hosts (by way of the XP12000/XP10000/SVS200) to the
mapped external LU or use the mapped external LU for a Flex Copy pair, select Enable.

If you do not suppress I/O from hosts to the mapped external LU, select Disable (for example,
for use with XP External Storage).

If you set the emulation type to something other than OPEN-V, IO 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 the software products other than XP Flex Copy

(such as XP Cache LUN, XP Auto LUN, XP Continuous Access, XP Continuous Access Journal
XP Business Copy, or XP Snapshot), set IO Suppression mode to Disable.

CAUTION:

To set IO Suppression mode to Disable, XP External Storage 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

).

To propagate the write I/O from the host to the external array asynchronously, select Enable.

To propagate the write I/O from the host to the external array synchronously, select Disable.

Data that is not written by the host (for example, data written by XP Business Copy) is
asynchronously destaged to the external array regardless of the Cache Mode setting.

If you set the IO Suppression mode to Enable, Cache Mode becomes Disable.

CAUTION:

If you select Disable, XP Cache LUN's bind mode cannot be set.

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

Displays the Select Paths pane (

Figure 43 (page 82)

). 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

80

Configuring external LUs

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