Data Replication Manager Windows-Based Server with Single Host Bus Adapter - Application Notes

Solution Behavior
6 Application Notes – Data Replication Manager Windows-Based Server with Single Host Bus Adapter
Solution Behavior
This section describes the setup of the solution in a Normal state and the behavior of the total solution
upon failure of certain components.
The Normal Situation
Before you can determine that a failure has occurred, you need to know the status of the Normal state.
Throughout this document, a server named mitersaw is used. The HSG80 presents three storage units
(D1, D2, and D3) to this server. Each unit is an RCS. The RCSs of D1 (drive letter K) and D3 (drive
letter M) are part of the same association set, and therefore are online to the same controller. The unit
D2 (drive letter L) is another association set and is online to the other controller. The Secure Path for
Windows main screen that shows this Normal state setup is in Figure 2.
Figure 2: Secure Path Manager main screen
The settings applied to Secure Path for Windows are:
• Auto Failback: This option specifies whether a logical unit number (LUN) must fail back to the
original controller after the restoration of a failed path. Although this option is generally disabled
in more standard DRM configurations, it must be enabled in single FC HBA server configuration.
• Load Distribution: This option specifies whether I/Os need to be balanced between the two
FC HBAs in the server. Because the server has only one FC HBA, this option must be disabled.
• Path Verification: This option enables a path verification that periodically determines the status of
available storage unit paths. Problems can be detected and corrected through this background
testing of activity and availability, ensuring path integrity. This option must be enabled.
• Polling Interval: 5 seconds.