The VMware HCX Interconnect integrates with ESXi to perform migrations based on the vMotion protocol for live powered on virtual machines, and with VMware NFC for cold migrations on powered off virtual machines.

HCX vMotion

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 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.

  • VMs with Raw Disk Mapping in compatibility mode (RDM-V) can be migrated.

  • 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.

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.