HCX and Virtual Machine Snapshots

HCX Migration Types and Snapshots

HCX provides several options for Virtual Machine migrations.  Powered on Virtual Machines can be moved with HCX vMotion or HCX Bulk Migration or powered off Virtual Machines and templates using HCX Cold Migration.

HCX does not generate or use snapshots for any of these migration types.  

With HCX vMotion, HCX participates in vMotion and proxies the vMotion protocol securely to the remote cluster (without requiring the source and remote vMotion networks to be joined or reachable in any way).

HCX Bulk migration uses VMware’s Host-based Replication technology to synchronize data to a remote target, and HCX Cold Migration uses VMware’s NFC protocol to move the powered off Virtual Machines or templates.

HCX Migration Options – Remove Snapshots

The HCX migration wizard includes a Remove Snapshots option (selected by default if snapshots are present).Screenshot 2018-08-02 22.49.12.png

In the HCX User Guide – Migration Options  it is stated like this:

“Remove Snapshots: This option allows HCX to consolidate snapshot files prior to migrating the Virtual Machine.  If there are snapshots present, the option will be checked by default”.

Regardless of the migration type, and option selected, Snapshots will not be migrated to the remote site by HCX.  

Here is what happens:

HCX vMotion migrations when the VM has snapshots

HCX will delete the snapshot(s) before proceeding with vMotion relocate operations:

  • HCX vMotion streams will be interrupted if snapshots are present.
  • Unchecking the box may result in a failed pre-migration validation or a failed HCX vMotion migration attempt.

HCX Bulk migrations when the VM has snapshots

HCX Bulk migrations of powered on Virtual Machines, if there are snapshots present, the option will be selected automatically, but HCX handles snapshots differently.

  • HCX Bulk migration will not fail even when snapshots present.
  • Snapshots are never migrated to the remote site.  The end effect with or without the option checked is that HCX will consolidate the LWD streams and the replicated VM will not have snapshots.

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