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vStorage API

Introduced for the first time in vSphere the vStorage API are specific functions to permit an integration more thight with external storage functions. Note that there also other integration module that are coverd in the PSA framework. For more information see:

vSphere Storage API – Storage Awareness (VASA)

This is a new set of APIs introduced in vSphere 5.0 that will enable VMware vCenter Server to detect the capabilities of the storage array LUNs/datastores, making it much easier to select the appropriate disk for virtual machine placement or the creation of datastore clusters. vSphere Storage APIs – Storage Awareness can also provide help in facilitating, for example, the troubleshooting process or conversations between vSphere and storage administrators. Storage capabilities, such as RAID level, thin or thick provisioned, replication state and much more, can now be made visible within VMware vCenter Server either via “system-defined capabilities,” which are per-datastore descriptors, or via attributes that are exposed via Storage Views and SMS API. vSphere Storage APIs – Storage Awareness aims to eliminate the need for maintaining massive spreadsheets detailing the storage capabilities of each LUN that are needed to guarantee the correct SLA to virtual machines.

For other info see: Overview vSphere Storage API for Storage Awareness (VASA) e A Deeper Look at VASA.

vSphere Storage APIs – Array Integration (VAAI)

This set of API was introduced for the first time in vSphere 4.1 and permit to offload specific storage operations to supported disk arrays for unparalleled performance and efficiencies. With Storage APIs for Array Integration, vSphere can perform key operations faster and consume less CPU, memory and storage bandwidth.

A lot of improvements are included in vSphere 5, like:

  • thin provisioning support
  • hardware acceleration for NAS
  • T10 Compliancy

See also:

 vStorage APIs for Data Protection (VADP)

This API was introduced in vSphere 4.0 and takes the benefits of Consolidated Backup and makes them significantly easier to deploy, while adding several new features that deliver efficient, scalable backup, and restore of virtual machines.
Like Consolidated Backup, this API make it possible to offload backup processing from ESX servers, ensuring that you deliver the best consolidation ratios without disrupting applications and users. The vStorage API for Data Protection enables backup tools to directly connect the ESX servers and the virtual machines running on them without any additional software installation. They add the ability to enable backup tools to do efficient incremental, differential, and full-image backup and restore of virtual machines.

See also: vStorage APIs for Data Protection (VADP)

Backup compatibility

The most important think is that seems that VADP in vSphere 5.0 is still compatible with the one from 4.0. What does it mean? That backup programs that works from ESXi 4.x can work also on vSphere 5 (I’ve just tested Veaam Backup 5.0.2 and seems to work fine also with the new environment).


Virtualization, Cloud and Storage Architect. Tech Field delegate. VMUG IT Co-Founder and board member. VMware VMTN Moderator and vExpert 2010-24. Dell TechCenter Rockstar 2014-15. Microsoft MVP 2014-16. Veeam Vanguard 2015-23. Nutanix NTC 2014-20. Several certifications including: VCDX-DCV, VCP-DCV/DT/Cloud, VCAP-DCA/DCD/CIA/CID/DTA/DTD, MCSA, MCSE, MCITP, CCA, NPP.