In this blog post, we are going to discuss the concepts about how you can do the cross vCenter Migrations of your workloads. This allows you to move VMs, hosts, and Clusters from one vCenter server to another vCenter server as per your technical requirements. Cross vCenter Migration introduced in vSphere 6.0 onwards.
What Cross vCenter Migrations means, Let’s understand it with an example.
Let suppose you have two vCenter servers named VC-01 and VC-02. You want to migrate resources from VC-01 to VC-02. The resources means virtual machines, ESXi hosts, and clusters data. We can represent it as VC-01 <=> VC-02.
Prerequisites for Cross vCenter Migration:
There are few prerequisites for cross vCenter migrations.
- The source and destination vCenter servers and ESXi hosts must be running version 6.0 or later.
- It requires an Enterprise Plus license.
- Both vCenter Servers must be in Enhanced Linked Mode and must be in the same vCenter SSO(Single Sign-On) domain to migrate VMs using the vSphere Web Client.
- Both vCenter Server instances must be time-synchronized with each other for correct vCenter Single Sign-On token verification.
- For the migration of computing resources only, both vCenter Server instances must be connected to the shared virtual machine storage.
- When using the vSphere APIs/SDK, both vCenter Server instances may exist in separate vSphere Single Sign-On domains.
Prerequisites for Networking
There are few network port required for the migration:
- Port 8000 and 902 should be open for vMotion and NFC between ESXi.
- Port 443 between both vCenter Servers.
- Port 443 between vCenter Server and the ESXi server (Using this port vCenter server allows to ESXi hosts to establish the secure connection)
Virtual Machine Networking Migration
Virtual machine networking configuration has some limitations for cross vCenter Migration. Let’s have a look at the below table:
| Source Type | Destination Type | Supported |
| Distributed Switch | Distributed Switch | Yes |
| Distributed Switch | Standard Switch | No |
| Standard Switch | Standard Switch | Yes |
| Standard Switch | Distributed Switch | Yes |
Other Component Migration
There are metadata associated with each virtual machine, hosts, and clusters. Let’s see what migrates and what does not.
Data that migrates:
- Any snapshots associated with VMs.
- Any notes for VMs.
- Memory and swap reservations are moved.
- Reservations, limits, and shares (RLS) are moved.
- Shares and Limits for virtual disks are moved.
- Advanced Settings for VMs are moved.
- EVC mode for Cluster will be retained.
- In vCenters, The vSphere Tags, any custom attributes, and permission are moved.
- Cluster level settings such as DRS automation level, admission control policy, Any DRS rules, All HA definitions will be moved as it is.
However, It is recommended to have a note of all your cluster-level settings before the migration. In case of any mismatch at the destination, you can revert it back.
Data that do not migrate:
- Any tasks, events, and alarms will not move.
- Any performance history data related to VMs, and Hosts will not move.
- vApp Membership does not moved.
- VM storage policies per VMDK may not moved.
There are three possible ways for Cross vCenter Server Migrations.
- Manual Migration
- Automated Migration
- Cross vCenter Workload Migration Utility
Manual Migration
You can also migrate the resources manually. You can follow steps for the guidance:
- First Log in to the destination vCenter Server.
- Create a datacenter here.
- Now under datacenter create folder whatever you want to name it.
- Manually create clusters as per source vCenter server.
- Manually add hosts to the cluster. (Before proceeding you need to disconnect hosts from source vCenter.
Automated Migration
You can also use scripting to migrate the cross vCenter objects.
Cross vCenter Workload Migration Utility
This utility allows users to easily migrate virtual machines in bulk from a graphical user interface between vCenter servers using the Cross-vCenter vMotion feature. However, This tool is supported officially by VMware.
Let’s have some features of this utility.
- This is a UI-driven workflow for VM migration through a vSphere Client plugin and a standalone UI.
- Provides REST API for automating migration tasks.
- Works with vCenter Servers in the same or in different SSO domains
- Supports migration to/from VMware Cloud on AWS
- Enables batch migration of multiple VMs in parallel
- Integrates with the host/cluster/resource pool menu of the vSphere Client inventory tree
- Auto-populates inventory for ease of management
- Monitor workload migration progress through vCenter Server tasks
- Register sites to store vCenter Server information
You can the official documentation here for better understanding about the utility.
You may also refer the guidance from vmwarearena.
Reference:
- Network Compatibility Checks During vMotion Between vCenter Server Instances
- Long-Distance vMotion requirements in VMware vSphere 6.0
- Migrate VM between two vCenter joined to different SSO domain
[Also read] VMware VCenter Server Appliance(VCSA) 6.7 Installation