HP XP External Storage Software - Manual (Page 108)

• I/O TOV: Time over value for I/O to the external LU
• Qdepth: Number of Read/Write commands that can be issued (queued) to an external LU at
one time
• Path Watch: Time period beginning when the connection of all paths to the external LU is down
and ending when the external LU is blocked
• Mode: How the local array manages alternate paths when defined. Possible values:
• 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: Uses all of the set paths at the same time to execute I/Os to the external LU, 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 alternate paths
Use the Path 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 internal 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 Available 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
Configured 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 cancel settings, right-click the setting in the Preset list, and select Delete.
6. Click Apply. A confirmation message appears.
7. Click OK.
Configuring external LUs 108