HP Hitachi Dynamic Link Manager Software - Manual (Page 40)

6-10 . After a path status is changed to online, the path can be selected as a
useable path by HDLM in the same manner as automatic path switching.
When using the Thunder 9500V series, or Hitachi AMS/WMS series, 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, since all the paths are owner
paths, the path to use is not switched even if you change the path status to
online by using the Path Management window or the online operation.
For details on how to change the path status in the Path Management
window, see the HDLM GUI Help.
Path Status Transition
This subsection explains the online and offline path statuses described in
Performing Failovers and Failbacks Using Path Switching on page 2-16 . There
are four types of online statuses, and three types of offline statuses. Each
type is described below. In the descriptions, an offline operation refers to
performing an offline operation by using the Path Management window in the
HDLM GUI, or by executing the dlnkmgr command's offline operation. For
details on the offline operation, see offline (Places Paths Offline) on page
6-6 .
The Online Path Statuses
The online path statuses are as follows:
• Online
I/Os can be issued normally.
• Online(P)
A state in which a path in the Online status is in the waiting-to-execute
status to be taken offline.
This status occurs in a cluster configuration only.
The Online(P) status indicates that the user has requested an Online
path to be taken offline, for a path that is connected to an LU that is
currently performing reserve processing. I/O operations can still be issued
normally until the reserve processing on the LU finishes. After the reserve
processing finishes, the offline operation request will be performed and
the path status will become Offline(C).
The (P) means pending, which indicates that the operation to take the
path offline is in the waiting-to-execute status (i.e. a request has been
made).
• Online(E)
An error has occurred on the path, but none of the other paths that
access the same LU are in the Online status.
If none of the paths accessing a particular LU are in the Online status,
one of the paths is changed to the Online(E) status. This ensures that
the LU can be accessed through at least one path.
2-20
HDLM Functions
Hitachi Dynamic Link Manager User Guide (for Windows(R))