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In the configuration described in Figure 6-24, a Global Mirror (Metro Mirror can also be used) solution is implemented between the Local System in Site A, the production site, and the Remote System 1 located in Site B, the primary disaster recover site. A third system, Remote System 2, is located in Site C, the secondary disaster recover site. Connectivity is provided between Site A and Site B, between Site B and Site C, and optionally between Site A and Site C. 

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To implement a cascading-like solution, the following steps must be completed: 

1. Set up phase. Perform the following actions to initially set up the environment: 

c. Create the Global Mirror relationships between the Local System and Remote System 1. 

d. Create the FlashCopy mappings in the Remote System 1 using the target Global Mirror volumes as FlashCopy source volumes. The FlashCopy must be incremental. 

e. Create the Global Mirror relationships between Remote System 1 and Remote System 2 using the FlashCopy target volumes as Global Mirror source volumes. 

f. Start the Global Mirror from Local System to Remote System 1. 

After the Global Mirror is in ConsistentSynchronized  state, you are ready to create the cascading. 

2. Consistency point creation phase. The following actions must be performed every time a consistency point creation in the Site C is required. 

a. Check whether the Global Mirror between Remote System 1 and Remote System 2 is in stopped  or idle  status, if it is not, stop the Global Mirror. 

b. Stop the Global Mirror between the Local System to Remote System 1. 

c. Start the FlashCopy in Remote Site 1. 

