Software User Manual

• Single: Uses only the path with the highest priority (primary path) to execute I/Os to
the external LU. If selected, the second-highest priority alternate path is enabled only
if a maintenance operation or failure affecting the primary path occurs. That is, the
external array contains Active/Passive (for example, MSA) or Asymmetrical Active/Active
controllers (for example, Hitachi 9500V).
• Multi:UsesallofthesetpathsatthesametimetoexecuteI/OstotheexternalLU,
distributing the workload. That is, the external array contains Symmetrical Active/Active
controllers (for example, XP).
• Previous and Next buttons
If you select multiple external LUs in the Device list, click Previous to change the Alternate Path list to
the external LU appearing just above the currently displayed LU. Click Next to change the Alternate
Path list to the external LU appearing just below the currently displayed LU.
• OK button
Closes the Path Setting window, and returns to the LU Operation pane. Contents specified in the Path
Setting window appear in blue italics in the Device list, and settings appear in the Preset list.
• Cancel button
Cancels all alternate path setting operations, closes the Path Setting window, and returns to the
LU Operation pane.
Defining al
ternate paths
Use the Pat
h Setting window to define alternate paths.
1. Select the LU Operation tab. The LU Operation pane appears.
2. In the Device tree, select the external LU group number. Information about the external LU mapped
as an inte
rnal LDEV appears in the Device list.
3. In the Device list, right-click the external LU, and select Path Setting. The Path Setting window appears.
The Configured Paths table displays detailed information about one currently defined path and the
alternate paths. The Available Paths table displays paths that can be set as alternate paths.
4. In the Av
ailable Paths table, right-click the row of the path to be defined as an alternate path,
and select Add.
The selected path is defined as an alternate path, and detailed information appears in the
Configur
ed Paths table.
5. Click OK. The Path Setting window closes, and the LU Operation pane appears.
Selected rows appear in blue italics in the Device list. Specified contents also appear in the Preset
list. To check details on intended operations, right-click the setting in the Preset list, and select Detail.
To canc
el settings, right-click the setting in the Preset list, and select Delete.
6. Click
Apply.Aconfirmation message appears.
7. Click OK.
The alternate path defined in the Path Setting window is applied to the local array, and the specified
conte
nts appear in the Device list.
If errors occur during alternate path operations, failed settings and error codes appear in the Preset
list. To check error messages, right-click the failed setting, and select Detail.
Changing a defined alternate path priority
To change the alternate path's priority, use the Priority Up and Priority Down commands displayed in
the Path Setting window (Figure 52).
• Priority Up: Raises the priority of the path selected in the Alternate Path list.
• Priority Down: Lowers the priority of the path selected in the Alternate Path list.
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Configuring external LUs