What’s New VSphere 9.0

June 19, 2025
No Comments

By Ali Hamedi – VMware & Storage Infrastructure Specialist

In this post, we want to talk about the most important new features in VSphere 9.0:

  • Licensing
    • vSphere 9.0 requires a minimum of 16 cores per CPU even if a CPU has fewer than 16 cores. If a CPU has more than 16 cores, additional CPU licenses are required
    • If your environment is running vSphere 8 and NSX 4.x, and you upgrade them to version 9, you will still need to use the VCF Operations appliance for licensing, even if you are not using VMware Cloud Foundation (VCF) in your environment. This is one of the significant changes in VCF 9.0
    • The initial license that is automatically created in VCF Business Services console after you purchase a subscription is called a default license. The default license is a pool of capacity from all active subscriptions of the same product in the same Site ID. Available capacity is displayed in the unit of measure for the specific product. For example, if you purchase a VCF subscription for 500 cores, you receive a default license for 500 cores of VCF and you also receive a default license of 500 TiBs of vSAN, which are added in a separate license. If, on top of that, you purchase a vSAN add-on subscription for 200 TiBs, the new number of TiBs is added to your default vSAN license, and its capacity becomes 700 TiBs.
    • There are two types of licenses – primary licenses, such as VMware Cloud Foundation and VMware vSphere Foundation licenses, and add-on licenses, such as vSAN add-on capacity or VMware Private AI Foundation with NVIDIA licenses. You no longer license individual components such as NSX, HCX, VCF Automation, and so on. Instead, for VCF and vSphere Foundation, you have a single license capacity provided for that product. For example, for VMware Cloud Foundation, the single license capacity provided for that product is VMware Cloud Foundation (cores). This is a primary license and you must assign it to your environment before you can assign an add-on license. Components are licensed automatically after you assign the primary license to a vCenter instance. For VCF and vSphere Foundation, you also receive VMware vSAN (TiB)capacity. You also receive VMware vSAN (TiB) capacity when you purchase vSAN as an add-on. The vSAN TiB license is called an add-on license.
    • Primary licenses are the licenses for VCF and vSphere Foundation. They are per core based. The only assets in your environment which consume the capacity of your primary licenses are ESX hosts. To calculate the capacity you need for your environment, you need the total number of the physical CPU cores for each physical CPU on all ESX hosts in your environment. Most products have a minimum consumption rule of 16 cores per physical CPU. CPUs that have fewer than 16 cores consume 16 cores. For example, if you have 1 ESX host in your inventory, with 1 CPU, and 8 CPU cores per CPU, this ESX host will use 16 cores of your license total capacity because it is the minimum license capacity.
    • To license your vCenter instance, assign either the VCF or vSphere Foundation license to your Center
    • You don’t have any option to insert a license directly from ESXi. You need to license your ESXi’s by VCenter
  • Increased minimum boot-bank size for ESX to 1 GB
    • With ESX 9.0, the minimum boot-bank size for ESX is up from 500 MB to 1 GB. ESX 9.0 boot-banks are provisioned at 1GB or 4GB to accommodate essential system software. Environments upgraded from previous versions with a 500 MB boot-bank automatically migrate to the new 1 GB or 4 GB boot-bank during the installation process. A minimum of 32 GB of system disk space is required for proper operation.
  • Reduced downtime upgrade is integrated with vCenter High Availability (HA) deployment
    • Reduces downtime to less than 5 minutes under ideal network, CPU, memory, and storage conditions.
  • Supported Upgrade Paths
  • Memory Tiering
    • ESX 9.0 officially launches the Memory Tiering capability, which enables you to add NVMe devices locally to an ESX host as tiered memory. Memory tiering over NVMe optimizes memory utilization by allocating and moving VM memory pages between faster dynamic random access memory (DRAM) and NVMe devices on the host. This allows you to improve the host CPU utilization by increasing memory footprint and workload capacity, while reducing the total cost of ownership
    • Memory Tiering combines DRAM (Tier 0) with the slower NVMe memory (Tier 1) to provide contiguous memory. Memory pages from NVMe are used only for VM memory allocations on an ESX host.
    • With the Memory Tiering feature, you can increase the workload capacity with a minimal impact on performance. This allows you to add more VMs and workloads to the ESX host, thereby better utilizing the available CPU resources.
    • By default, the Memory Tiering feature is deactivated.
    • You can activate the Memory Tiering feature and configure the NVMe device on the ESX host to serve as tiered memory. Memory Tiering integrates seamlessly with DRS, which continuously monitors the ESX hosts within a cluster and places VMs to load-balance memory usage across the cluster.
    • You can configure Memory Tiering either at a cluster or at a ESX host level.
  • vSphere Requirements for Memory Tiering
    • Component Requirements
      • vCenter 9.0 and later
      • ESX 9.0 and later
    • Make sure that the ESX host is placed in Maintenance Mode before you activate, deactivate, or reconfigure Memory Tiering.
    • NVMe devices used for Memory Tiering must be of a similar class to a vSAN cache device. Note that an already configured vSAN cache or data disk cannot be used for Memory Tiering
      • NVMe devices cannot be over fabric or ethernet. They must be installed locally on the ESX host
      • Configure NVMe devices with a tier partition. The tier partition cannot be larger than 4 TB
      • Hot-plug and prepare to remove are not supported for an NVMe device being used for Memory Tiering.
      • NVMe devices that are already part of a datastore, such as vSAN, cannot be used for Memory Tiering
  • vSphere vMotion Optimizations for vGPU Workloads
  • Virtual Hardware Version 22
  • Support Boot over NVMe/FC SAN and NVMe/TCP SAN
  • Snapshot enhancements
    • ability to resume snapshot consolidation for offline VMs
  • vCenter Appliance is now PhotonOS version 5.0
    • vCenter 9.0, the default size of the log partition is 50 GB for any vCenter deployment
    • Broadcom branding on the object and component icons in Center
  • Virtual Private Cloud (VPC) in Center
    • VCF 9.0 introduces Virtual Private Cloud (VPC) support in vCenter, enabling administrators to create VPCs and define subnets, either private or publicly advertised, to expose VMs externally by using external IPs.
  • Custom Enhanced vMotion Compatibility (EVC)
    • Starting with vCenter 9.0, you can create a custom EVC mode and apply it to your clusters or virtual machines. The custom EVC mode feature set is based on the highest set of features available in all selected hosts. If your vCenter instances are part of an Enhanced Linked Mode group, you can select hosts or clusters from any vCenter instance part of the Enhanced Linked Mode group
  • Storage 4K native support

About the Author

Ali Hamedi is a VMware and Storage Infrastructure Specialist with over 20 years of experience in enterprise virtualization, vSAN, and cloud technologies. He currently works at CIBC as a Consultant Network Infrastructure Engineer in Canada, focusing on VMware solutions.