HP XP7 Storage - Manual (Page 45)

Online operation: Online operation performed by executing the dlnkmgr
command's online operation.
Offline operation: Offline operation performed by executing the dlnkmgr
command's offline operation.
#1
Also when an error occurs in all the paths to an S-VOL in the Online(D)
status.
#2
When I/O operations are processed on an S-VOL.
If there is only one available online path for an LU, it cannot be placed offline
by using the Path Management window or by executing the offline
operation. This ensures that the LU can always be accessed by at least one
path. For details on the offline operation, see offline (Places Paths Offline)
on page 6-6 .
If an error occurs in the only available online path for an LU, the status of the
path will change to Online(E).
If you are using the automatic failback function, after the path has recovered
from the error, HDLM will automatically place the path online. There are,
however, the following exceptions:
• When you are using intermittent error monitoring, sometimes, the path in
which the intermittent error occurred is not automatically placed online
after the path has been recovered from the error. If this happens,
manually place the path online. If the only other online path is in the
Online(E) status when the path is recovered from the error, the path
recovered from the error might be placed online automatically. For
details, see Figure 2-14 What Will Happen When an Intermittent Error
Does Not Occur on a Path on page 2-28 .
• There are cases in which the path is automatically placed online even if
you are not using the automatic failback function. If a piece of hardware
that supports the Windows plug-and-play function is removed, HDLM will
place the path associated with that hardware offline, as well. If the
hardware is then re-installed, HDLM will automatically place the path back
online. However, this is the case only when there is no other cause or
reason for the path being placed offline. In this case, because HDLM will
automatically place the path back online without using the automatic
failback function, you do not need to manually place the path online.
When you use the LU dynamic deletion function, the Online(E) path will be
deleted. Therefore, that path is not displayed in the Path Management
window. Also, the view operation does not display the Online(E) path.
Note:
If there is a path failure immediately after a path is taken offline by using
either the an HDLM command or the HDLM GUI, 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 Functions
2-25
Hitachi Dynamic Link Manager (for Windows®) User Guide