The VMware HCX Interconnect integrates with ESXi to perform vMotion migrations for powered on virtual machines, and with Cold Migration for powered off virtual machines.
VMware HCX vMotion can transfer a live Virtual Machine from a VMware HCX-enabled vCenter Server to a VMware HCX-enabled destination site (or from the VMware HCX-enabled destination site towards the local site). The vMotion transfer captures the virtual machine's active memory, its execution state, its IP address, and its MAC address. Migration duration depends on the connectivity, including both the bandwidth available and the latency between the two sites.
HCX Cold Migration
Cold migration uses the same network path as VMware HCX vMotion to transfer a powered-off virtual machine. During a cold migration, the Virtual Machine IP address and MAC address are preserved. Cold migrations must satisfy the vMotion requirements.
Requirements and Limitations for VMware HCX vMotion and Cold Migration
VMware HCX Interconnect Tunnels must be up/active.
VMware HCX vMotion requires 100 Mbps or above throughput capability.
The virtual machine hardware version must be at least version 9 or higher.
The underlying architecture, regardless of OS, must be x86.
- Virtual machines with Raw Disk Mapping in compatibility mode (RDM-V) can only be migrated using Cold Migration & Bulk Migration.
- Forward vMotion based migrations are supported from source ESXi hosts running versions 5.5 to 6.7. Reverse vMotion based migration is only supported with vSphere 6.0 and higher. Reverse migrations to ESXi 5.5 hosts can be accomplished with HCX Bulk migration.
- VMware NFC is used as the primary protocol during Cold Migration and as a secondary protocol during HCX vMotion..
Note: The HCX Interconnect uses a Network Profile configuration dedicated to the vMotion traffic. This configuration does not include the Cold and vMotion NFC traffic. HCX always uses its Management interface for Cold and vMotion NFC traffic. In deployments where ESXi servers use a dedicated Provisioning vmkernel for NFC traffic, the HCX continues to route Cold and vMotion NFC traffic through the Management interface.
Virtual Machine Restrictions for HCX vMotion
Virtual machines with the following attributes are not supported for migration.
Shared VMDK files.
Attached virtual media or ISOs.
Virtual Machine Hardware Version 8 or below.
- Although concurrent VMware HCX vMotion migrations can be initiated up to the vSphere limits, VMware only supports serial VMware HCX vMotion migrations between a source and destination site. For simultaneous migrations in parallel, select VMware HCX Bulk Migration.
- VMware HCX vMotion defaults to Opportunistic mode for per-VM vMotion Encryption if it is set to Required. During the migration operation - the mode is changed to Opportunistic during the migration initialization, and then set back to Required after the migration is completed.
Virtual Machines with Change Block Tracking (CBT) can be migrated, but HCX disables CBT.
- If either the source or destination vCenter version is 6.0 or earlier, VMware vCenter tags attached to a virtual machine are not retained during migration. Tags can be created manually for those virtual machines after migration.
- VMware software appliances (including, but not limited to vCenter Server, NSX Manager, Site Recovery Manager) cannot be migrated with HCX vMotion migration.