Make sure that the host meets the minimum hardware configurations supported by ESXi 8.0.

Hardware and System Resources

To install or upgrade ESXi, your hardware and system resources must meet the following requirements:

  • Supported server platform. For a list of supported platforms, see the VMware Compatibility Guide.
  • ESXi 8.0 requires a host with at least two CPU cores.
  • ESXi 8.0 supports a broad range of multi-core of 64-bit x86 processors. For a complete list of supported processors, see the VMware Compatibility Guide.
  • ESXi 8.0 requires the NX/XD bit to be enabled for the CPU in the BIOS.
  • ESXi 8.0 requires a minimum of 8 GB of physical RAM. Provide at least 12 GB of RAM to run virtual machines in typical production environments.
  • To support 64-bit virtual machines, support for hardware virtualization (Intel VT-x or AMD RVI) must be enabled on x64 CPUs.
  • One or more Gigabit or faster Ethernet controllers. For a list of supported network adapter models, see the VMware Compatibility Guide.
  • ESXi 8.0 requires a boot disk of at least 32 GB of persistent storage such as HDD, SSD, or NVMe. A boot device must not be shared between ESXi hosts.
  • SCSI disk or a local, non-network, RAID LUN with unpartitioned space for the virtual machines.
  • For Serial ATA (SATA), a disk connected through supported SAS controllers or supported on-board SATA controllers. SATA disks are considered remote, not local. These disks are not used as a scratch partition by default because they are seen as remote.
    Note: You cannot connect a SATA CD-ROM device to a virtual machine on an ESXi host. To use the SATA CD-ROM device, you must use IDE emulation mode.

Storage Systems

For a list of supported storage systems, see the VMware Compatibility Guide. Starting with ESXi 8.0, you cannot use software adapters for Fibre Channel over Ethernet (FCoE), only hardware FCoE adapters.

ESXi Booting Requirements

In vSphere 8.0, support for legacy BIOS is limited and booting ESXi hosts from the Unified Extensible Firmware Interface (UEFI) is recommended. With UEFI, you can boot systems from hard drives, CD-ROM drives, or USB media. vSphere Auto Deploy supports network booting and provisioning of ESXi hosts with UEFI. If your system has supported data processing units (DPU), you can only use UEFI to install and boot ESXi on the DPUs. For more information on VMware plans to deprecate support for legacy BIOS in server platforms, see Deprecation of legacy BIOS support in vSphere.

ESXi can boot from a disk larger than 2 TB if the system firmware and the firmware on any add-in card that you are using support it. See the vendor documentation.

Storage Requirements for ESXi 8.0 Installation or Upgrade

For best performance of an ESXi 8.0 installation, use a persistent storage device that is a minimum of 32 GB for boot devices. Upgrading to ESXi 8.0 requires a boot device that is a minimum of 8 GB. When booting from a local disk, SAN or iSCSI LUN, at least a 32 GB disk is required to allow for the creation of system storage volumes, which include a boot partition, boot banks, and a VMFS-L based ESX-OSData volume. The ESX-OSData volume takes on the role of the legacy /scratch partition, locker partition for VMware Tools, and core dump destination.
Note: In ESXi 8.0, the ESX-OSData volume is considered a unified partition and the separate components, such as /scratch and VMware Tools, are consolidated into a single persistent OSDATA partition.

Other options for best performance of an ESXi 8.0 installation are the following:

  • A local disk of 128 GB or larger for optimal support of ESX-OSData. The disk contains the boot partition, ESX-OSData volume and a VMFS datastore.
  • A device that supports the minimum of 128 terabytes written (TBW).
  • A device that delivers at least 100 MB/s of sequential write speed.
  • To provide resiliency in case of device failure, a RAID 1 mirrored device is recommended.

Legacy SD and USB devices are supported with the following limitations:

  • SD and USB devices are supported for boot bank partitions. The use of SD and USB devices for storing ESX-OSData partitions is being deprecated and best practice is to provide a separate persistent local device with a minimum of 32 GB to store the ESX-OSData volume. The persistent local boot device can be an industrial grade M.2 flash (SLC and MLC), SAS, SATA, HDD, SSD, or a NVMe device. The optimal capacity for persistent local devices is 128 GB.
  • If you do not provide persistent storage, you see an alarm such as Secondary persistent device not found. Please move installation to persistent storage as support for SD-Card/USB only configuration is being deprecated.
  • You must use an SD flash device that is approved by the server vendor for the particular server model on which you want to install ESXi on an SD flash storage device. You can find a list of validated devices on partnerweb.vmware.com.
  • See SD card/USB boot device revised guidance on updated guidance for SD card or USB-based environments.
  • To chose a proper SD or USB boot device, see Boot device guidance for low endurance media (vSphere and vSAN).

The upgrade process to ESXi 8.0 from versions earlier than 7.x repartitions the boot device and consolidates the original core dump, locker, and scratch partitions into the ESX-OSData volume.

The following events occur during the repartitioning process:
  • If a custom core dump destination is not configured, then the default core dump location is a file in the ESX-OSData volume.
  • If the syslog service is configured to store log files on the 4 GB VFAT scratch partition, the log files in var/run/log are migrated to the ESX-OSData volume.
  • VMware Tools are migrated from the locker partition and the partition is wiped.
  • The core dump partition is wiped. The application core dump files that are stored on the scratch partition are deleted.
Note: Rollback from ESXi 8.x to a version of ESXi earlier than 7.x is not possible due to the repartitioning process of the boot device. To use a version of ESXi earlier than 7.x after upgrading to version 8.0, you must create a backup of the boot device before the upgrade, and restore the ESXi boot device from the backup. Rollback from ESXi 8.x to 7.x is possible as long as no changes to the bootbank partitions have been made and no corrupt partition is detected.

If you use USB or SD devices to perform an upgrade, best practice is to allocate an ESX-OSData region on an available persistent disk or a SAN LUN. If persistent storage or a SAN LUN are not available, ESX-OSData is automatically created on a RAM disk. VMFS can also be used for ESX-OSData partition.

After upgrade, if ESX-OSData resides on a RAM disk and a new persistent device is found on subsequent boots, and this device has the setting autoPartition=True, ESX-OSData is automatically created on the new persistent device. ESX-OSData does not move between persistent storage automatically, but you can manually change the ESX-OSData location on a supported storage.

To reconfigure /scratch, see Set the Scratch Partition from the vSphere Client.

To configure the size of ESXi system partitions, you can use the systemMediaSize option. For more information, see Boot option to configure the size of ESXi system partitions.

In Auto Deploy installations, the installer attempts to allocate a scratch region on an available local disk or datastore. If no local disk or datastore is found, installation fails.

For environments that boot from a SAN or use Auto Deploy, the ESX-OSData volume for each ESXi host must be set up on a separate SAN LUN.