HP Hitachi Dynamic Link Manager Software - Manual (Page 170)

3. Creating an HDLM Environment
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is enabled. To prevent an intermittent error from reducing I/O performance, we
recommend that you monitor intermittent errors when automatic failback is enabled.
When intermittent error monitoring is enabled, you can specify intermittent error
conditions. The default value for the intermittent error-monitoring interval is 30. The
default value for the number of error occurrences is 3.
The system assumes that an intermittent error has occurred if the specified number of
times that the error needs to occur is reached during the specified monitoring interval.
A path that is assumed to have an intermittent error is excluded from performing an
automatic failback. Intermittent error monitoring starts right when the path is
recovered from the error by performing an automatic failback. Monitoring is
performed on each, individual path.
When a value of 2 or more is specified for the number of times an error needs to occur,
make sure that the condition shown in (3) Setting Up the Automatic Failback Function
is satisfied.
To determine whether a path is invalid for an automatic failback, you can use the
results of the
dlnkmgr
command's
view
operation.
• Setting up intermittent error monitoring by using the
set
operation
The following is an example of setting up intermittent error monitoring by using
a command:
>dlnkmgr set -iem on -intvl 20 -iemnum 2
on
specifies that intermittent error monitoring is to be used. To disable
intermittent error monitoring, specify
off
. When you set this parameter to
on
,
you can specify intermittent error conditions by using the
-intvl
and
-iemnum
parameters. Specify the monitoring interval for an intermittent error in the
-intvl
parameter, and the number of times that the error needs to occur in the
-iemnum
parameter. When these parameters are omitted, the default values of 30
and 3 are used, respectively.
(5) Setting Up the LU Deletion Function
For details on the LU deletion function, see 4.7.2 Deleting an LU Dynamically.
Table 3-15: LU Deletion Function Values shows the possible values for the LU
deletion function.