HP StorageWorks XP Remote Web Console Software - Manual (Page 24)

24 Preparing for External Storage XP operations
For more information about path status, see ” Adding alternate paths by selecting multiple external LUs
(Add Paths) ” on page 91.
• Alternate path mode is Multi mode
Figure 5 shows an example of when the alternate path mode is Multi mode. When an error occurs in
one path, I/Os execute using paths other than the error path.
NOTE: As you restore the error path, use of the restored path automatically resumes.
Figure 5 Alternate path mode is Multi mode
NOTE: In Multi mode, active I/O load balancing occurs across external array ports and
controllers. The XP and EMC DMX are examples of external arrays that use Multi mode.
• Alternate path mode is Single mode
Figure 6 shows an example of when the alternate path mode is Single mode. When an error occurs in
the path used for I/Os, the I/O execution path switches to the path with the second highest priority.