vSphere 6.5 introduced support for VVol replication but on day 1 of the vSphere 6.5 GA there wasn’t a single storage vendor that supported it. VMware has a special Compatibility Guide category specifically for VVol support that shows which storage vendor arrays support VVols and additional information on supported array models, firmware and protocols. One additional piece of information in those listings is a field labeled Feature, this field is used to indicate support for additional VVol special features, it is not intended to display array capabilities that are exposed to VVols.
Prior to vSphere 6.5 I have only seen 2 types of features displayed in some vendor listings, Multi-vCenter support and VASA Provider High Availability support. The Multi-vCenter support simply means a storage array can support connecting to multiple VASA Providers when you have more than one vCenter Server in your environment. The VASA Provider High Availability support was mainly intended for external VASA Providers to indicate they had some type of mechanism in place to protect the VP in case of a failure (i.e. VM down).
Now with vSphere 6.5 there is a new feature listing called VVols Storage Replication which is an indication that a storage array supports the new VVol replication capability in vSphere 6.5. Note that a storage array can be certified to support VVols in vSphere 6.5 but unless they have the VVols Storage Replication feature listed they do not support VVol replication.
As of today there are only 7 storage vendors that are listed as supporting VVols in vSphere 6.5: Fujitsu, HPE, HDS, Huawei, IBM, NEC and Nimble, at the vSphere 6.5 launch there were only 4. but there is currently only one storage vendor that supports VVol replication, which is Nimble. For comparison purposes there are 17 storage vendors listed as supporting VVols in vSphere 6.0. So while support for VVols replication is now available, most storage vendors are not ready to support it yet. Having seen first hand the amount of engineering effort it takes to support VVols replication I can understand why I can count on my nose the amount of vendors that support it.
Another potential speed bump for customers wanting to implement VVol replication is the very limited documentation and support for performing replication related operations such as planned and unplanned failover, failback and failover testing. VMware introduced some new PowerCLI cmdlets to do some of these operations, but customers have to write their own scripts to make it work and it can get a bit complicated to do so especially when trying to recover from an unplanned failover. Currently there is no support for vRealize Orchestrator or vCenter Site Recovery Manager with VVol replication to help automate those operations. There is also currently no support for doing a test failover via PowerCLI.
I know VMware is working to try and get some sample scripts and documentation around this as well as expand PowerCLI support and integrate it into SRM. The only documentation I have been able to find so far is this page from Nimble Storage which has some good information about their implementation of VVols replication. So if you are anxious to start using VVol replication check with your storage vendor to see where they are at with it, I suspect you will see support slowly trickle out among the storage vendors, I know of one storage vendor in particular that will be supporting it fairly soon.
It’s great to see VVols evolve to support replication as it was a key missing feature that was holding some people back from using VVols. Now that VMware has delivered VVol replication support as part of VASA 3.0 in vSphere 6.5 the ball is in the storage vendors court to enable it within their arrays. As VVols continues to mature I look forward to seeing more hands go up when I’m speaking to groups and asking who is using it as there are a lot of great benefits to using the VVols storage architecture.
