To return to normal operation after systems A and B fail:
1.On system C, fail link BC over to C.
T1 and D1 remain read-only on C. T2 becomes read-write on C.
2.When system B becomes available again, on system C, restore link BC.
3.On system B, accept the restored link.
4.On system C, begin and complete data recovery on link BC.
When data recovery is complete, T1 and D1 are read-only on B and C. T2 becomes read-write on B and read-only on C, and replication resumes on link BC.
System B automatically recreates link AB without the primary system IP addresses or hostname from the inbound link AB in link BC.
5.When system A becomes available again, take either of these actions:
oIf link AB still exists on A:
1.On system A, restore link AB.
2.On system B, accept the restored link.
3.On system B, begin and complete data recovery on link AB.
When data recovery is complete, T1 and D1 become read-write on A and remain read-only on B, and replication resumes on link AB.
oIf link AB no longer exists on A, follow the steps for option one or option two in the table below.
o
Option one | Option two | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
T1 and D1 become directly included in link BC, which still includes T2, and become read-write on B. |
||||||||||||
|
2. Optionally, create a new replication chain B4C4A:
T1, D1, and T2 are read-write on B and read-only on C and A, and replication starts on link CA. |
||||||||||||
|
N/A | ||||||||||||
When data recovery is complete, T1 and D1 are read-write on A and read-only on B and C, and replication restarts on link AB. |
© 2017 Hitachi Data Systems Corporation. All rights reserved.