HP StorageWorks XP Remote Web Console Software - Manual (Page 96)

– Disconnect: Connection to the external array or LU was stopped using the Disconnect
Subsystem or Disconnect Volume command.
– Unavailable: External array replied Unavailable. The external array demands to
change the connected port. After the status becomes Unavailable, the primary path
changes to the alternate path that is in the Standby status. When the primary path
changes, the path status becomes Normal.
– Backoff: External array replied Backoff. The path status is Waiting for Recovery
because a temporary error occurred in the external array's volume. Even if the primary
path's status becomes Backoff, the primary path does not change to the alternate
path immediately. After the error recovery, the status becomes Normal. If you cannot
recover the status from the error, the path status changes to the other status.
– Device check error: The target volume in the external subsystem is not accessible,
even though the external volume was mapped.
– Medium error: The target volume in the external subsystem has become inaccessible.
◦ 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.
96 Configuring external LUs