vSphere 6 has been in public beta for several months now and this week at VMworld some of the new capabilities are now public. vSphere 6 remains in beta for a future release (sign up here!), but let’s take a quick look at some of the new features that have been announced (so far)
SMP for Fault Tolerance
Just a quick overview here. Fault Tolerance is a pretty neat feature that can keep a second copy of a VM in complete lockstep for HA purposes. The second VM has it’s own VMDKs which can sit on a different datastore or SAN, while each CPU transaction is maintained on both servers. This is a great way to provide redundancy for applications which can’t afford to lose cycles during a fail-over event, but the Achilles heel was always that it was limited to a single vCPU.
VMware announced earlier this year that it would be discontinuing vSphere Heartbeat and now we know why. With Fault Tolerance being able to support VMs with up to 4 vCPUs in vSphere 6, it would no longer be necessary for high availability to be provided by in-OS clustering. VMs of up to 4 vCPUs and 64GB of RAM can now enjoy the benefits of VMware Fault Tolerance.
Some of the vMotion improvements announced include being able to vMotion across difference vCenter instances, across routed networks (this “may” work now but was never formally supported), and perhaps most importantly long distance vMotion.
The latency tolerance for vMotion will be increased from 10ms to 100ms in vSphere 6! With this generous of a tolerance for latency so many more vMotion scenarios would now be a possibility without the normal geographic penalties. Personally, I think VMware should demonstrate this capability by vMotioning a VM to an EVO:RAIL cluster in a hot air balloon with a 4G LTE wireless network.
This is a huge feature in my opinion – a whole evolution beyond what VAAI introduced — and rather than try to drill deep here I’ll try to stick to a simple overview. A vVol is a new logical construct that appears as a datastore in your admin tools, which allows the virtual disk to be a “first class citizen” in storage (versus the LUN or volume). A vVol does not use VMFS but is a new abstraction layer that enables object based storage access (with your VMDKs being the objects).
I found a good illustration of a “before and after” view of all these pieces on Greg Schulz’ StorageIO blog which are shown below:
There’s several things going on here which I’ll just quickly touch on. First there is one protocol end point now versus many as illustrated below. This enables more API capabilities to be exposed and if I understand correctly, VMware has plans to allow third parties to develop filter APIs here.
vVOLS are hardware integrated much like VAAI which means the storage vendors will develop their definitions for the API to activate the capabilities of their storage arrays. For example one capability is the ability to offload the snapshot function from a copy-on write flat file – to have the storage array handle it. While snapshots are an awesome feature of vSphere (which are not backups by the way), I’m not a big fan of the copy-on-write delta file method. I’ve seen snap chains 40+ levels deep (without anyone knowing) and snaps that were left open for months until the datastore filled up. By offloading snapshots and other operations to the storage array these things can be handled a lot more effectively.
I didn’t even get to storage profiles yet which allow to define what characteristics a certain VMDK should have. There’s many scenarios here but at a high level just removing the complexity of LUNs and RAID characteristics from admins is a big deal. When a VM is provisioned the admin needs only to select the storage policy (or one is forced for them) and the desired settings are enforced without the complexity being visible.
With that very basic into a highly encourage you to read one or more of the following blog posts which go FAR deeper into vVOLs, how they work, and their benefits.
- Are VMware VVOLs in your virtual server and storage I/O future? (StorageIO Blog)
- Virtual Volumes (VVOLs) Tech Preview (Cormac Hogan – VMware)
- Virtual Volumes Beta (Rawlinson Rivera – VMware)
This is a new logical construct within vSphere which allows you to enjoin multiple vSphere clusters into one construct to force consistent policy settings, provide a top level management point and facilitate cross-cluster vMotion.
Improved Web Client
The web client has significantly improved with each release but many (like me) find the web client to be a bit slow at times. It’s clear that VMware has spent some time on this as from using the beta I can assure you that there is a significant improvement in response time between the 6.0 and 5.5 web clients.
That’s just a quick summary of some of the features that were mentioned in the general session. Even more details should be available over time as vSphere 6 grows closer and closer to a GA (General Availability) release. If you’re anything like me, you probably can’t wait for vSphere 6 – perhaps the biggest feature I’m looking forward to is vVols. Until then, happy virtualizing!