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vSphere 6.7: Feature Overview

Today, 20 years and one day after celebrating its founding, VMware released vSphere 6.7, the latest iteration of its hypervisor and data center management platform. Although this update isn’t as feature-packed as the previous (6.5) release from November 2016, it does include some interesting new features that savvy data center operators can utilize to increase productivity.

vSphere 6.7 was released in beta about six months ago. The beta was open to the general public, but the participants were required to agree to a nondisclosure agreement (NDA). VMware was serious about the NDA, and very little information or insight was leaked about the product. Having worked with it during the beta period, here are the most useful and/or innovative features I found in vSphere 6.7.

Instant clone API: VMware’s virtual desktop infrastructure (VDI) product, Horizon, has had the ability to use instant clone technology for quite some time. Instant clones use shared memory and delta disks to track the changes made to a parent image; by using this technology, new virtual machines (VMs) can be created very quickly — think seconds rather than minutes — and consume a fraction of the memory and disk space of a full clone VM, since only the changes that have been made to the parent image are stored for an instant clone image.

However, the main restriction Horizon imposed on instant clone technology was that it was exclusively limited to Horizon virtual desktops. VMware has eliminated this limitation in vSphere 6.7 by releasing the API for instant clones; you can now create instant clones for whatever use you want. This is very powerful technology, and ripe for future development.

vGPU: One of the new features in vSphere 6.7 getting a lot of attention is the ability to suspend and resume VMs that use virtual GPUs (vGPU). vGPU technology allows for a single, physical GPU to be split up and used by multiple VMs.

But for the most part, once a VM uses a vGPU, it’s tied to the server on which the physical GPU is based. With this release, a VM can be suspended on a host and resumed later. This might seem minor, but it has some large implications. Many of the VMs that use vGPU are high-value VMs, and having the ability to increase their availability is an important consideration in maximizing their resource usage.

Quick Boot: vSphere 6.7 has the ability to do a quick boot of an ESXi host in which only the kernel, rather than the hardware, is rebooted. Any admin who’s ever experienced a server running through its battery of tests during a hardware reboot will appreciate this feature. The caveat is that only certain servers and only native drivers are supported with this feature, so make sure you look at hardware compatibility beforehand.

vSphere Client: Flash-based interfaces are painful from both a developer and user perspective. Many I’ve had to look for the right browser Flash version to support vSphere Web Client, VMware’s Flash-based client. With vSphere 6.7, VMware claims that their HTML5-based client, vSphere Client (a name uncomfortably close the Flash client’s name), now has about 90% of the functionality of the vSphere Web Client.

From personal experience, I can report that the new vSphere Client seems to be more responsive and has a cleaner look than the Flash-based client. Yes, you’ll need to learn a few new workflows to use the new client, but for the most part ,common daily tasks are fairly intuitive. Hopefully, VMware will have a site that lists which functionalities are supported with the vSphere Client, as they did with the vSphere Client in vSphere 6.5. After spending many frustrating hours with the Flash client, I’ll dance on the vSphere Web Client’s grave when the vSphere client is 100% feature complete.

Per-VM EVC: One nice but occasionally frustrating aspect of having a VM cluster is that you can mask off specific CPU features of the hosts within a cluster to bring them down to a least-common-denominator status. This condition allows VMs to be vMotioned to any of these hosts. VMware calls this feature “Enhanced vMotion Compatibility,” or EVC.

The frustrating part of EVC in its previous incarnations is that it’s been an all-or-nothing proposition, with all the VMs crippled in the same manner. vSphere 6.7 provides the ability to have an EVC policy for each VM. If some VMs need to take advantage of advanced CPU features, you can specify which CPU features to mask off and which features leave as-is.

PMem Devices: One trending datacenter topic is the use of persistent DRAM memory, known as non-volatile double in-line memory module (NVDIMM) devices, for persistent memory (PMem) storage. PMem devices are still quite rare, but if you have applications that need the lowest possible latency, you’ll be using this technology. vSphere 6.7 supports PMem in one two ways: as vPMemDisk, which looks like a datastore, or as a virtual NVDIMM (vNVDIMM), which is presented directly to guest OSes.

Virtual Hardware version 14: In order to support NVDIMM, Trusted Platform Module (TPM), Microsoft Virtual-Based Security (VBS) and IO Memory Management, VMware’s released a new version of its virtual hardware: 14.

Other Notable Changes

  • VMware is phasing out VMFS3 datastores, and vSphere 6.7 will automatically upgrade VMFS3 datastores to VMFS5 when mounted. Even though VMFS6 is now available, VMware went with upgrading VMFS3 datastores to VMFS5, as vSphere 6.0 and earlier systems only support VMFS5 datastores. As such, if you have an environment that contains vSphere 6.0 or earlier systems, you’ll want to only use VMFS6 datastores on systems that won’t be accessed by the earlier versions.
  • There were minimal changes to the maximum configurations for this vSphere release, but there has been an increase in the number of devices that can be attached to a host. As with all vSphere releases, VMware has added support for some new hardware and dropped support for others. Before considering whether or not to update your system, check the VMware HCL to verify that your system is supported, as many popular yet older systems have been dropped off the HCL.

Since vSphere 6.7 embraces technology not yet common in most data centers, such as PMem devices and VMs that use vGPU, this can be seen as a forward-looking release. On the other hand, features such as the HTML5-based vSphere Client, quick boot, and per-VM EVC, will immediately benefit common data centers. Other capabilities, such as the instant clone API, will be exploited to bring some additional benefits to the datacenter in the short term.

VMware’s been around for two decades, is the eigth largest software company in the world, and has worked hard to stay relevant in the data center and avoid the commoditization of the hypervisor. Although vSphere 6.7 isn’t a feature-rich release, it does show that VMware is still showing leadership and is committed to its vSphere product line. vSphere 6.7, as well as the release notes (which include all new features) can be downloaded here.