Migrating virtual machines to vSAN from other clusters or datastores

Products

• VMware vSAN

Issue/Introduction

This solution provides steps to two different methods of migrating virtual machines from iSCSI/FC/NFS to vSAN if they are on different clusters or datastores.

vSAN is a distributed, object-based storage system, which is very different from other classic storage types mentioned above. The VM folders which can be seen in the vsanDatastore are "VM Namespaces", which are a special type of vSAN object. These contain the vmware.log files, VMX configuration file, snapshot and VMDK descriptor files (which point to the actual vSAN object data).

These VM Namespace objects are not intended to contain any large file/binary data like VMDK flat files (VM-flat.vmdk), as those folders are also limited to a maximum size of 255 GB and UNMAP is not supported on these. Hence for migrating virtual machines to a vSAN storage, please follow below outlined steps.

Environment

VMware vSAN (All Versions)

Resolution

Method 1 - Shared-Nothing vMotion

Note: If any CPU or DRS affinity rules and resource pools are in use, please make sure these are in place on the vSAN cluster before the migration.

1. Right click on the VM


2. Change Both compute resource and storage 


3. Choose destination vSAN cluster


4. Select the Storage Policy matching your requirements and select the vSAN datastore. Then proceed with the next step.

5. Verify the selected target network and adjust if needed

6. Select vMotion priority (default is with high priority)

7. Review settings and click Finish to start the process

Method 2 - Storage vMotion

1. Present current SAN storage to new ESXi hosts running vSAN.
2. Using Storage vMotion migrate the VMs to vSAN, with similar steps as in Method 1 above (select "Change storage only").
3. After migrating all virtual machines and its data, un-present SAN LUN's from the vSAN cluster if no longer needed.