If you customize you own script to be used when running a failover plan, you can override the following parameters for the Custom Script step:
To allow the script to run inside the guest OS of a processed VM, it is required that Microsoft PowerShell 3.0 and .Net Framework 4.0 must be installed on each VM for which you enable this step.
Defines whether the step is critical for the VM recovery.
If you mark the step as Critical, its failure for a critical VM will halt the plan.
Defines whether the script will run on the Veeam Backup & Replication server or in-guest of the VM.
Veeam Backup Server
Credentials required to gain access to the in-guest OS.
Applies only if the Execute Location parameter value is set to Guest OS.
Maximum amount of time (in seconds) for the step to execute.
Number of retries that will be attempted if the step fails on the first try.
Failback & Undo Failover Action
Defines whether the step will be executed during the Failback and Undo Failover operations.
Defines whether the step will be executed during plan testing in a virtual lab.