Does storage vmotion uses VAAI from datastore to datastore copy?

Yes, Storage vMotion (SvMotion) leverages VMware vStorage APIs for Array Integration (VAAI) when performing the datastore-to-datastore copy. VAAI is a set of storage APIs introduced by VMware to offload certain storage-related tasks from the ESXi host to the storage array. These APIs help in improving storage performance, reducing host CPU overhead, and accelerating various operations, including Storage vMotion.

When a Storage vMotion operation is initiated to move a virtual machine’s disk files from one datastore to another, the use of VAAI allows the transfer to be optimized and more efficient. Specifically, VAAI enables the following offloaded operations during the datastore-to-datastore copy:

1. Full Copy (Hardware Assisted Move): VAAI allows the source storage array to directly copy the virtual machine’s virtual disks to the destination storage array without involving the ESXi host for intermediate data transfers. This offloading significantly reduces the load on the ESXi host and speeds up the migration process.
2. Fast Clone (Hardware Assisted Copy): When the virtual machine has multiple snapshots, VAAI can offload the creation of linked clones (snapshots) on the destination datastore. The fast clone operation allows the creation of linked clones on the destination side without transferring the entire content of each snapshot from the source datastore.
3. Hardware Assisted Locking: VAAI provides hardware-assisted locking, which allows the storage array to handle lock management more efficiently during Storage vMotion operations. This reduces contention and improves overall performance during the migration process.

By leveraging VAAI, Storage vMotion can perform datastore-to-datastore copies more rapidly and with minimal impact on the ESXi hosts. The actual availability of VAAI features depends on the storage array’s support for VAAI. Most modern storage arrays are VAAI-enabled, and VAAI support is a standard feature for most enterprise-grade storage solutions.

To check whether your storage array supports VAAI and its specific capabilities, you can refer to the VMware Compatibility Guide and consult the storage vendor’s documentation. Additionally, make sure that your ESXi hosts are properly configured to take advantage of VAAI features and that VAAI is enabled on both the source and destination storage arrays before performing Storage vMotion operations.

Do we use VAAI in clone operations from one datastore to other ?

VMware vStorage APIs for Array Integration (VAAI) is not utilized when performing standard VM cloning operations from one datastore to another. VAAI is primarily designed to offload certain storage-related tasks, such as Storage vMotion and hardware-assisted copy/move operations, to the storage array, resulting in improved performance and reduced host CPU overhead.

However, for regular VM cloning (also known as template-based cloning) that is initiated from within the vSphere Client or using the PowerCLI New-VM cmdlet with the -Template parameter, VAAI is not involved. Instead, the cloning process typically follows a different path:

1. Template Deployment: When deploying a virtual machine from a template stored in one datastore to another, the vSphere Client or PowerCLI will create a new VM by deploying the template’s virtual disks and configuration files to the destination datastore. The cloning process is managed by the vCenter Server or directly by the ESXi host, and it does not utilize VAAI.
2. Virtual Disk Copy (VMDK Copy): The template-based cloning process involves copying the template’s virtual disks (VMDK files) from the source datastore to the destination datastore. This copy operation is typically performed by the vCenter Server or ESXi host and does not utilize VAAI offloading.
3. Configuration and Customization: Once the virtual disk copies are in place, the VM’s configuration files and settings are created or updated based on the template’s specifications. Any customization specifications or guest OS settings are also applied during this step.

It’s important to note that while VAAI is not directly used for standard VM cloning, it can be leveraged for other data operations like Storage vMotion and cloning operations involving snapshot-related tasks (e.g., creating linked clones from a snapshot). VAAI capabilities depend on the specific storage array’s support and compatibility with VAAI features.

As technology and VMware capabilities continuously evolve, it is possible that newer versions of VMware vSphere or future enhancements may incorporate VAAI features or other storage offloading technologies into standard VM cloning operations. Always refer to the official VMware documentation and release notes for the latest information on VAAI support and feature integration in VMware vSphere. Additionally, consult your storage vendor’s documentation to determine the level of VAAI support and integration for your specific storage array.