HP Hitachi Dynamic Link Manager Software User Manual
Page 58
2. HDLM Functions
34
the
Online(E)
paths have been deleted.
• The
Offline(E)
paths are assumed to have had an intermittent error, and
are thus excluded from automatic failbacks.
• The SCSI devices are connected to the
Offline(E)
paths.
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 6.4 offline (Places Paths Offline).
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 2-13: What Will Happen When an
Intermittent Error Does Not Occur on a Path.
• 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 command or the
HDLM GUI, and then make sure that the status has changed to
Offline(C)
. If
it is still
Offline(E)
, retry the offline operation.