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vSphere APIs Storage Awareness (VASA) July 5, 2012

Posted by vbry21 in VMware blogs.
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vSphere APIs Storage Awareness (VASA)

Working on my vCenter I realise that I can see my LUN is 500GB, but I don’t know how it’s configured, is it RAID 1, RAID 5 or RAID 10, how many spindles do I have etc.

vSphere administrators do not have visibility in VMware vCenter Server into the storage capabilities of the storage array on which their virtual machines are stored. Virtual machines are provisioned to a storage black box. All the vSphere administrator sees of the storage is a logical unit number (LUN) identifier, such as a Network Address Authority ID (NAA ID) or a T10 identifier.

VMware vSphere Storage APIs – Storage Awareness (VASA) is a set of software APIs that a storage vendor can use to provide information about their storage array to vCenter Server. Information includes storage topology, capabilities, and the state of the physical storage devices. Administrators now have visibility into the storage on which their virtual machines are located because storage vendors can make this information available.

VMware vCenter Server collects the information from a storage array by using a software component called a VASA provider. A VASA provider is written by the storage array vendor. The VASA provider can exist on either the storage array processor or on a standalone host. This decision is made by the storage vendor. Storage devices are identified to vCenter Server with a T10 identifier or an NAA ID. VMware recommends that vendors use these types of identifiers so that devices can be matched between the VASA provider and vCenter Server.

The VASA provider acts as a server in the vSphere environment. VMware vCenter Server connects to the VASA provider to obtain information about available storage topology, capabilities, and state. The information is viewed in the VMware vSphere Client. A VASA provider can report information about one or more storage devices. A VASA provider can support connections to a single or multiple vCenter Server instances.


In all this gives us as administrators so much more information that can allow us to make informed decisions regarding placement of our VMs. Rather than trust (rather hash sorry, SAN administrators are all trustworthy) the SAN administrator, we can see how the storage is configured.