VMware has announced this new storage feature set called Virtual Volumes or VVols with vSphere 6.0. I am not going to describe all great reasons why you need VVols and how it improves your storage efficiency, I leave that to VMware…
A quite remarkable is the fact that HP 3PAR was selected as reference storage platform in the Fibre Channel area.
So far we were using VMware with the typical Datastore model. This means that a storage array provides a volume to an ESXi server, formats this volume with a file system called VMFS and so becomes a datastore, and this datastore will hold multiple VM’s in multiple subdirectories.
This means within a subdirectory on that datastore, for each VM there will be separate files created for the VM config, 1 or more disks (VMDK), swap and memory.
New in vSphere 6.0 there is a new model available being the VVols model.
One of the big differences here is the fact that now every VMDK, VMconfig and SWAP file will be provisioned as a separate (VVol) volume within the array. And not a specific file on a datastore.
This new VVol datastore a.k.a. Storage Container holds a loose association of VVols. These separate volumes are created specifically for the VM config, VMDK, swap and memory objects.
Important here is that Config, VMDK, swap and memory can have different storage capabilities, depending on the features of the array underneath.
Since there is no sub-directory hierarchy, each volume must be labeled (meta-data) so both VMware and the array can identify which volume belongs to which VM. This is all handled by the communication between the vSphere platform and the array through the VASA provider.
VVol: VMware virtual volume
VASA: VMware vSphere Storage APIs for Storage Awareness. Does a lot more than just “awareness” in version 2.0.
VASA Provider or Storage Provider: A storage‐side software component that acts as a web service interface (API) for the vSphere environment. It can either run in the array or outside the array. In 3PAR’s implementation it runs in the array.
Storage Container: A location where VVols are stored. Appear as a “datastore” in the vSphere user interface. Can be the whole 3PAR array or a 3PAR virtual domain.
Protocol Endpoint: I/O de-multiplexor which can communicate to the VVols on behalf of ESXi. These PEs are used to establish a data path from the VMs to their respective virtual volumes on demand.
This Protocol Endpoint is rather important in this whole story since PE enables us getting around the 256 LUN limit in vSphere. Since each file will become his own volume means that your storage array will have to host 1000’s of volumes in an average environment. Now I understand why they have chosen 3PAR as reference array. 😉 The PE will be seen as an administrative LUN with LUN ID 256 with a size of 512 bytes. That’s it.
PE is used to establish a data path from the VMs to their respective VVols on demand. Think of the PE as a management construct not an I/O construct. Once a VVol has been bound via the PE, the I/O goes through the PE to the VVol.
Also important is the VASA provider. For most of the array’s currently on the market, additional software must be installed somewhere on a physical or virtual server. Good to know that the VASA provider runs directly on the 3PAR array:
The VVol storage container will be seen as a new type of datastore while creating a VM:
Finally there will be also additional CLI instructions specific to VVols: showvasa, setvasa, startvasa, stopvasa, showvvolvm (at launch)
3PAR StoreServ will be the first storage array that will provide space reclamation via the zero-detect engine in the 3PAR ASIC with VVols on a per-VM basis.
Further in combination with Priority Optimization 3PAR can guarantee QoS at the application and/or VM level for most efficient and real-time control of VMs performance.
Finally snapshotting will allow thousands of recovery points on a per VM basis.
Storage indeed changes with VVols on 3PAR… Great job!
As soon as I get more information on VVols I will keep you posted. Or even better let’s deploy it asap in the Bitcon datacenter… 😉
And here is the VMware official page on VVols.
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