Wednesday, 12 November 2014

vVOLS (Virtual Volumes)

# Jagadeesh Devaraj

I believe its a hot and trending topic now in internet. By now you guys might heard a lot about the vVols at VMworld 2014 or through various forums and the reason it is important to manage the end-to-end Infrastructure. The vVols takes cares of end-to-end Infra from compute of storage at the virtual machine (VM) and its VMDK ( vDisk) level. Virtualization meant VMs and vDisks are the unit of management at the compute layer. VMware® Virtual Volumes is meant to bridge the gap by extending the paradigm to storage specifically on VMware vSphere® deployments.

What is vVols : 

VVOLs is a provisioning feature for vSphere 6 that changes how virtual machines (VMs) are stored and managed. ( Information source :

VVOLs is an out-of-band communication protocol between vSphere and storage. It allows VMware to associate VMs and vDisks with storage entities, and allows vSphere to offload some storage management functions, like provisioning of VM's to storage. This offloading allows virtualization administrators to get the same performance and scalability through the VMware tools they may expect through their storage.The VM is then automatically placed on the storage array that fits those requirements.

VVOLs' other advantage is the ability to snapshot a single VM instead of just the traditional snapshot of an entire logical unit number that may house several VMs. This feature saves wasted space on the data store and reduces the amount of administrative overhead.

Note : To use VVOLs, the storage hardware has to support the vStorage APIs for Storage Awareness (VASA). VMware introduced VVOLS at VMworld 2011 during a technical preview session.

VM granular data management : 

If you have dealt with VMware datastores, either VMFS or NFS, for any length of time you have run into the granularity problem: you have several hundred virtual machines on a datastore, and you need to recover the one that somebody trashed. If you are using array-based snapshots or replication it is much easier to restore the entire volume than it is to restore a single VMDK.

VVols solves this problem by making each VMDK an addressable object on the storage array. That means that with VVols on VNX you can take array snapshots of individual VMDKs and restore them on a case-by-case basis.


Another design point of VVols is scalability. VVols are designed to scale from thousands of objects up to millions, based on the capabilities of the underlying storage array. This means that whether you are deploying desktops with a single VMDK per VM or email servers with multiple VMDKs, each snapped every hour, you have the ability to deploy at the proper scale.

VVols on VNX will scale across the product family, from low-end arrays suitable for hosting hundreds or thousands of VMs to enterprise-class arrays supporting orders of magnitude more VMs.

Policy Based Management

If you are going to manage that many VVols, you need a system. Nobody wants to manage thousands of VMs individually, so VVols (technically VASA 2.0), includes support for Storage Policy Based Management. This allows you to specify policies, such as Gold, Silver, and Bronze (or Engineering, Sales, and Finance) for classes of service. These policies can specify attributes like performance, backup schedule, thin vs. thick, etc. Once you specify a policy, you can order up a dozen new Engineering desktops, for instance, and vCenter will do the work of finding storage that advertises the required capabilities. Need to upgrade some virtual servers from Bronze to Silver? No problem, just change the profile and vCenter (with a little help from the storage array) will make it happen.

VVols on VNX will allow storage administrators to expose the value-added features of VNX storage to vCenter, including FAST Cache, Multi-tiered pools, Virtual Provisioning, VNX Snapshots, and much more.

You can explore these features soon with the GA version which is going to be launched earlier next year.

Excited about vVols ? Stay tuned for more updates.


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