HP XP Racks - Manual (Page 42)

#2
When the following conditions are satisfied, a path that has been
determined to have an intermittent error also becomes subject to
automatic failback:
¢
All the paths connected to an LU are Online(E), Offline(E), or
Offline(C).
¢
All the paths connected to an LU have been determined to have an
intermittent error.
¢
The processing of continuous I/O operations issued to an LU is
successful.
#3
This path is deleted when the AIX chdev command is executed on an
hdisk where an Online or Offline(E) path exists. To restore the deleted
path, remove the cause of the error and then execute the AIX mkdev -l
hdisk-name or cfgmgr command.
#4
When an Online or Offline(E) path exists among the paths that access
the same LU.
#5
One of the Offline(E) paths is changed to the Online(E) path.
#6
When an Offline(E) path exists among the paths that access the same
LU.
The last available online path for each LU cannot be placed offline by
executing the offline operation. This ensures access to the LU. For details
on the offline operation, see offline (Places Paths Offline) on page 6-6 .
If an error occurs in the last available online path for each LU, the status of
the path is changed to Online(E).
If you are using automatic failback, when the path recovers from an error,
HDLM automatically places the path online.
When you are using intermittent error monitoring, the path in which the
intermittent error occurred is not automatically placed online when the path
recovers from the error. In such a case, place the path online manually.
Note
If there is a path failure immediately after a path is taken offline by using
either the an HDLM command, the status might change from Offline(C)
to Offline(E). If an offline operation was just performed, wait about 2
minutes, check the path status by using an HDLM command, and then
make sure that the status has changed to Offline(C). If it is still
Offline(E), retry the offline operation.
2-22
HDLM Functions
Hitachi Dynamic Link Manager User Guide for AIX®