When a virtual machine with an RDM disk is cloned, the virtual disk is provisioned in thick regardless of the specified format.
Article ID: 434745
Updated On:
Products
Issue/Introduction
When performing a clone of a virtual machine (VM) that has Raw Device Mapping (RDM) disks attached, the following behavior is observed:
Despite selecting the "Thin Provision" option for the target virtual disks in the clone wizard, the resulting virtual machine disk (VMDK) files are created in the Thick Provision format.
Environment
vCenter Server 8.0 update 1 or later
Cause
This behavior is by design in the current product release.
When an RDM disk is cloned to a virtual disk, the cloning operation does not honor the specific thin provisioning request.
Resolution
To convert the disk to Thin Provisioning format after cloning, perform Storage vMotion.
step:
1.Right-click the virtual machine and select Migrate.
2.Select Change storage only.
3.Select Configure per disk and change the Disk format of the target disk to Thin Provisioning.
4.Select the destination datastore and complete the wizard.
For detailed steps, please refer to the KB below.
Changing the thick or thin provisioning of a virtual disk
Additional Information
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