Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide

Data Replication Manager Concepts 2–11
NOTE: If both links are severed, and the initiator configuration is functional, the system
administrator must determine which site to use.
Failback
The failback method, full copy or fast-failback, will be determined by the enabling of
Logging or Failsafe switches, the selected operation mode, and whether the failover is
planned or unplanned as detailed in Table 2-1. The table also shows the availability of
Association Set switches, ORDER_ALL and FAIL_ALL.
Table 2–1 Data Replication Manager Switch Settings
Logging Enabled Association Sets
Logging Error
Mode
Failsafe
Operation
Mode
Failover Failback Order
All
Fail
All
Enabled Disabled Synchronous Planned Fast-
Failback
Settable Not Applicable
for DRM
Enabled Disabled Synchronous Unplanned Full Copy Settable Not Applicable
for DRM
Enabled Disabled Asynchronous
(switch to
Synchronous)
Planned Fast-
Failback
Settable Not Applicable
for DRM
Enabled Disabled Asynchronous Unplanned Full Copy Settable Not Applicable
for DRM
Logging is recommended for operations that can tolerate temporary
loss of currency at the target site.
Failsafe Enabled Association Sets
Logging Error
Mode
Failsafe
Operation
Mode
Failover Failback Order
All
Fail
All
Disabled Enabled Synchronous Planned Full Copy Not Applicable
for DRM
Settable
Disabled Enabled Synchronous Unplanned Full Copy Not Applicable
for DRM
Settable
Disabled Enabled Asynchronous Planned Full Copy Settable Settable
Disabled Enabled Asynchronous Unplanned Full Copy Settable Settable