Today we'll look at the latest improvements and performance enhancements in VMware vSphere 6.7 and recently the vSphere 6.7 Update 2 announced just few days ago.

vCenter Server operations are quicker since vCenter is able to handle more operations per second. Here are the details from VMware's testing:

  • 2x faster performance in vCenter operations per second
  • 3x reduction in memory usage
  • 3x faster Distributed Resource Scheduler (DRS) operations, such as virtual machine (VM) power-on

These optimizations will improve overall speed and latency. Clients will see reduced resource consumption due to DRS and reduced latency to generate VMotions for load balancing.

vCenter Server architecture now has a clear vision since with vSphere 6.7 update 2, VMware deprecates the use of external Platform Service Controllers (PSCs) and uses an embedded PSC installed together with vCenter Server.

This architecture is not only simpler to maintain but also supports vCenter Enhanced Linked Mode where you can link up to 15 vCenter Server instances in the embedded PSC topology. With this simplified architecture, you don't have to deploy load balancers.

ESXi Quick Boot ^

VMware Quick Boot is new feature introduced in vSphere 6.7 U1. If configured, the host boots faster; it can skip BIOS POST entries and just boot without going through the slow hardware check on I/O devices.

As you know, a regular reboot involves a full power cycle that requires firmware and device initialization. Quick Boot optimizes the reboot path to avoid this, saving considerable time in the upgrade process.

It works, and it's configurable via vSphere Update Manager (VUM), so your patching and upgrades complete much more quickly. Not all servers or configurations support the Quick Boot feature. VMware is working with major server hardware vendors.

The Update Manager UI will present Quick Boot as an option for servers that support the feature. If your hardware isn't supported, the option will be grayed out.

Configuration Maximums improvements ^

VMware has published new host maximums with vSphere 6.7 and lately 6.7 Update 2:

  • VM hardware version 15 brings scalability improvements (you can configure up to 256 vCPUs).
  • Maximum supported processors have increased from 576 to 768 logical CPUs.
  • Host memory has also increased from 12 TB to 16 TB of RAM.

These improvements will allow you to run very large enterprise applications, such as SAP HANA or other intensive enterprise workloads.

Persistent memory (PMem) ^

vSphere 6.7 has introduced persistent memory (PMem), a type of non-volatile DRAM (NVDIMM). It has approximately the same speed as a traditional RAM module, but the difference is that it can retain content across reboots—something traditional RAM cannot do.

vSphere 6.7 supports two modes of accessing PMem:

  • A virtual persistent memory disk (vPMemDisk) presents NVDIMM capacity as a local host data store that requires no guest operating system (OS) changes to use this technology.
  • Virtual persistent memory (vPMem) exposes NVDIMM capacity to the VM through a new virtual NVDIMM device. You add it as a virtual hardware device to your VM. The guest OSes use it directly as a block device.
Adding a new NVDIMM device

Adding a new NVDIMM device

This release has some limitations, however, so if you want to use this technology, you must be aware of the following:

  • vSphere High Availability (HA) will not protect a VM with a vPMem device.
  • You must exclude a VM with vPMem from a VM-level backup. If a VM was previously part of such a backup, disable Changed Block Tracking (CBT) before adding vNVDIMM to a VM.
  • You can vMotion a VM with vPMem, but a destination host must have a hardware NVDIMM device.

VMware has observed that vPMem can improve performance by up to 1.8x better throughput and 2.3x better latency compared to standard SSD technology.

Storage improvements ^

As for storage, VMware has improved storage stacks by adding the possibility to connect even more devices and attach more disks, compared to what was possible in previous release.

There are some improvements to vSphere 6.7 ESXi host storage maximums, which you'll find below:

  • Fibre Channel devices have increased from 512 devices per host to 1024.
  • Fibre Channel paths have increased from 2048 paths per host to 4096.
  • The number of virtual disks per VMware Paravirtual SCSI (PVSCSI) controller has increased from 16 disks to 64, which now allows for 256 disks per VM.

Network improvements ^

VMware vSphere 6.7 has the new vmxnet3 driver version. The latest version is version 4, supporting some new features, for example:

Offload for Geneve/VXLAN – Generic network virtualization encapsulation (Geneve) is a protocol used with the NSX-T product. So Geneve and virtual extensible LAN (VXLAN) offloading is now available in the vmxnet3 v4 driver. Performance testing of this feature showed a 415% improvement in throughput in a test that used a packet size of 64 K with eight flows.

Mellanox hardware support ^

Some of the latest native drivers support Mellanox hardware, which is very popular in enterprises.

vSphere 6.7 includes native drivers for the following Mellanox host channel adapters that support 40 and 100 gigabit-per-second speeds over InfiniBand, iWARP, and RDMA over Converged Ethernet (RoCE):

  • ConnectX-3 EN
  • ConnectX-3 Pro with VPI
  • ConnectX-4 with VPI
  • ConnectX-5 EN

VMware Tools improvements ^

The new virtual hardware version 15 made its appearance, which, as said, can bring some performance improvements for CPUs (up to 256 vCPUs per VM) and memory (up to 6 TB of RAM per VM).

Lastly, the vSphere 6.7 update 2 just announced has new support for Windows Server 2019 via VMware Tools 10.3.5.

The latest VMware Tools version (10.3.5) allows updating vmxnet3 drivers via Windows Update for Windows Server 2016.

Final words ^

VMware is continuously improving the vSphere suite to keep everything up to date and improve what needs improving. The vSphere 6.7 U2 announcement caught a lot of attention, but VMware hasn't specified when this version will be available for download.

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vSphere 6.7 U2 provides virtual hardware version 15 where you can create new guest OS VM templates from Windows Server 2019 or Red Hat Enterprise Linux (RHEL) 8.


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