Overview of scenarios for practicing at H3 for Metro Global Mirror

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This topic provides an overview of the scenarios for practicing at H3 for Metro Global Mirror.

Before you begin

Note: For simplicity, the following scenarios are geared toward the configuration where the session is running H1->H2->H3. The same options apply when in the configuration is running H2->H1->H3.

About this task

There are multiple methods to set up a practice mode at the remote site, H3 depending on the session type.
When using a cascaded Metro Global Mirror without Practice, you can issue the following commands:
  1. Start H1->H2->H3
  2. Suspend
  3. RecoverH3
  4. Start H1->H2

When the session state is Target Available at H3, you can practice you disaster recovery steps on H3 while continuing to run the real production I/O to H1. In this mode, the H1 to H2 Metro Mirror pairs will remain running and are considered the only participating role pairs.

When using a multi-target Metro Mirror - Global Mirror session, you can issue the following commands.

  1. Start H1->H2 H1->H3
  2. Suspend H1H3
  3. FailoverH3

When the session is in a Suspended (Partial) state and the H1-H3 pairs are Target Available, you can practice I/O on the H3 volumes which continuing to run production on the H1 volumes.

When using a cascaded Metro Global Mirror with Practice session or a multi-target Metro Mirror - Global Mirror with Practice session , you can issue the following commands:
  1. Start H1->H2->H3
  2. Flash

When you issue the Flash command on a Practice session, the session will consistently suspend the GM backend relationships and then create a FlashCopy from the I3 to H3 volumes. After a FlashCopy is created to H3 the session will be automatically restarted. This allows customers to practice I/O on the H3 volume while maintaining a full three site disaster recovery configuration.