Hitachi XP P9500 User Manual page 355

4. HDLM Operation
Figure 4-1: Overview of the Period Required to Respond to an Application's I/
O Request
As shown in the preceding diagram, when an HDLM device has two paths (SCSI
devices), the maximum period of time required to respond to the application's I/
O request is n1 + n2 seconds; where n1 indicates the timeout value specified for
the path that uses SCSI device A, and n2 indicates the timeout value specified for
the path that uses SCSI device B.
When using HDLM in a cluster environment, a node in the cluster may fail over
before the path completes failover. To avoid this, when you set up the failover
timeout value for the node by using cluster software, make sure that you specify
a period longer than the response time that is calculated as described in the
preceding note.
If a path error occurs while creating a file system, or formatting, or executing
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