The last replication cycle for the virtual machine failed. Encountered timeout event.

Why it happens

The server being replicated is under heavy load, which causes high disk I/O (read and write activity) on its attached disks. The replication cycle cannot read the changed data in time and times out.

Where you see it, and what it affects

The message names the affected VM and shows for agentless VMware to Azure replication through the Azure Migrate appliance. Check it in the Azure Migrate project under Manage > Server replication, or in the -Health output of Get-AzMigrateServerMigrationStatus. It affects one server. Microsoft says replication carries on and completes with a delay, so it slows the path to migration rather than stopping it.

How to fix it

1. 1

   Step 1

   Reduce load on the source server where you can (for example, move heavy jobs out of hours).

2. 2

   Step 2

   In Azure Cloud Shell (PowerShell) or any Windows PowerShell session with access to the project, run the health check cmdlet to see errors, possible causes and recommended actions.

3. 3

   Step 3

   If you take no action, Microsoft says replication still completes, only later than expected.

Get-AzMigrateServerMigrationStatus -ProjectName "migrate-project" -ResourceGroupName "rg-migrate" -MachineName "server01" -Health

Check that it is fixed

• Run Get-AzMigrateServerMigrationStatus with -MachineName and confirm the replication status, disk progress and time left are moving.
• In Manage > Server replication, confirm Last sync is recent and Replication health is Healthy.
• Confirm Migration status shows Ready to migrate once initial replication completes.

Sources

Full guide: How to migrate VMware, Hyper-V and physical servers to Azure →