StarWind Virtual SAN® VAAI (vStorage API for Array Integration) Configuration & Performance Guide
This document contains a guide for configuration and performance check of StarWind Virtual SAN® VAAI (vStorage API for Array Integration). It is intended for experienced StarWind users and VMware administrators, who want to decrease the workload caused on the network by using VAAI. It reveals how exactly one can check if VAAI is working properly and how productive it is.
VAAI (vStorage API for Array Integration) is a complex of technologies, designed to offload certain VM disk operations to the storage array. In this case, when working with the disk subsystem, the virtualization host commands the array to perform specific actions, without having to process all the data it traditionally had to.
VAAI support allows StarWind to offload multiple routine storage operations from the VMware hosts to the storage array itself. Thus, these operations are carried out much faster and with no impact on the hypervisor operation.
In the example provided in the document, the system has several mounted disks on ESX host. The properties of disk system show that hardware acceleration has Unknown status. Once an operation supported by VAAI (i.e. Copy/Paste of a virtual disk) is performed, VAAI will try to tune in.
Steps for checking if VAAI really works:
- Creating an ImageFile device in StarWind.
- Connecting the device to ESX-host.
- Turning on VAAI.
- Performing VM migration between mounted datastores with VAAI turned on.
- Migrating the VM with VAAI off.
- (Optional) Cloning or copying VMs between datastores.