Testing Disaster Recovery
Use the Failover Test operation to test that during recovery the virtual machines are correctly replicated at the recovery site. The Failover Test operation creates test virtual machines in a sandbox, using the test network specified in the VPG definition, as opposed to creating virtual machines in a production network, to a specified point-in-time, using the virtual disks managed by the VRA. All testing is written to scratch volumes. The longer the test period the more scratch volumes are used, until the maximum size is reached, at which point no more testing can be done. The maximum size of all the scratch volumes is determined by the journal size hard limit and cannot be changed. The scratch volumes reside on the storage defined for the journal.
The Failover Test operation has the following basic steps:
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The test virtual machines are created at the remote site using the network specified for testing in the VPG settings and configured to the checkpoint specified for the recovery. |
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The virtual machines are powered on, making them available to the user. If applicable, the boot order defined in the VPG settings is used to power on the machines. |
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Testing. The virtual machines in the VPG are created as test machines in a sandbox and powered on for testing using the test network specified in the VPG definition and using the virtual disks managed by the VRA. All testing is written to scratch volumes. The longer the test period the more scratch volumes are used, until the maximum size is reached, at which point no more testing can be done. The maximum size of all the scratch volumes is determined by the journal size hard limit and cannot be changed. The scratch volumes reside on the storage defined for the journal. Using scratch volumes makes cleaning up the test failover more efficient. |
Notes:
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Do not delete, clone, migrate to another host, or change the disk properties of any of the test virtual machines. |
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Do not delete the protected source VM during the test. |
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The test virtual machines are powered off and removed from the inventory. |
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The following tag is added to the checkpoint specified for the test: Tested at startDateAndTimeOfTest |
The tagged checkpoint can be used to identify the point-in-time to restore the virtual machines in the VPG during a failover.
Testing that recovery is accomplished successfully should be done periodically so that you can verify that a failover will work. Zerto also recommends testing all the VPGs being recovered to the same cluster together. For example, in a cluster, if the HA configuration in a cluster includes admission control to prevent virtual machines being started if they violate availability constraints, testing the failover of every VPG configured for recovery to this cluster, at the same time, will show whether the constraints are violated or not.
When configuring a VPG, specify the period between tests for that VPG in the Test Reminder field in the REPLICATION step of the Create VPG wizard.