Path Status Transition; The Online Path Status; The Offline Path Status - Hitachi XP P9500 User Manual

the path status is changed to online, HDLM selects the path to use in the
same way as for automatic path switching. When the Thunder 9500V Series,
or Hitachi AMS/WMS series is being used, HDLM selects the path to use from
online owner paths, and then from online non-owner paths. When the
Lightning 9900 Series, Lightning 9900V Series, Hitachi USP, Universal
Storage Platform V/VM, Virtual Storage Platform, Hitachi AMS2000 Series, or
Hitachi SMS is being used, because all the paths are owner paths, the path to
use is not switched even if you change the path status to online.

Path Status Transition

Each of the online and offline statuses described in
Failbacks Using Path Switching on page 2-15
statuses. The following explains the two online path statuses and the two
offline path statuses.

The Online Path Status

The online path statuses are as follows:
•
Online
I/Os can be issued normally.
•
Online(E)
An error has occurred in the path. Also, none of the paths that access the
same LU are in the Online status.
If none of the paths accessing a single LU are in the Online status, one of
the paths will be changed to the Online(E) status. All the paths that
access the same LU will not be in the offline statuses. This ensures access
to the LU.
The text (E) of Online(E) indicates the error attribute, which indicates that
an error occurred in the path.

The Offline Path Status

The offline path statuses are as follows:
•
Offline(C)
The status in which I/O cannot be issued because the offline operation
was executed. For details on the offline operation, see
Paths Offline) on page
The (C) means command, which indicates that the path was placed offline
by using the command.
•
Offline(E)
The status indicating that an I/O could not be issued on a given path,
because an error occurred on the path.
The (E) in Offline(E) indicates the error attribute, which indicates that an
error occurred in the path.
6-6.
HDLM Functions
Hitachi Dynamic Link Manager User Guide (for Solaris(R))
Performing Failovers and
is further subdivided into two
offline (Places
2-19