Migrating a vm from thick disk to thin

[Shanmugavadivel Mahali]

Hi Team, Good Day!

We are using VMware HCX version 4.11 to migrate virtual machines between datacenters using the Bulk Migration method.

At the source environment, several VMs have disks configured as:

Thick Provision Lazy Zeroed

Thick Provision Eager Zeroed

 

During the migration configuration, we explicitly selected the option to convert the disks to Thin provisioning.

 

However, after the migration completes, when we verify the disk format of the migrated VMs, the disks still appear as:

Thick Provision Lazy Zeroed

Thick Provision Eager Zeroed

 

They remain in the same format as the source instead of being converted to Thin as selected.

The destination storage is Dell EMC PowerFlex presented as VMFS datastores.

We would like clarification on why the disk format is not being converted to Thin despite selecting that option during the HCX migration job configuration.

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[Christopher Dooks]

With PowerFlex, is the disk provisioning type defined by storage profiles? If so, you need to select a storage profile which has thin provisioning selected. Storage profiles will override what provisioning method is selected in the migration.

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[Shanmugavadivel Mahali]

Hi Christopher Dooks,

Thanks for your response. 

I just wanted to give you more details about the migration.

Adding to the above, we have our VMs hosted in Source vCenter in a vSAN Cluster (object-based storage) and using thin disks type. We are migrating these VMs to Target vCenter where we have VMFS (Block) storage. We don't have any special storage policies configured on source or destination. 

We assume that this might be an expected behavior and would want to confirm.

Thanks in advance

Shanmugavadivel Mahali

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