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Install VMware ESXi 7 on a R710 with an Intel 55xx CPU

Follow along to install ESXi 7 on a R710. I tried running this same procedure with ESXi 6.7 media but it did not work. Something changed in ESXi 7.x which allows the install to complete when setting the legacy CPU mode, though I am not complaining! While I am able to run and create virtual machines there may be something that doesn’t work but I haven’t encountered any issues yet.

My R710 Specs

  • Xeon 5506 CPU (Unsupported Processor)
  • 64GB Ram
  • 1x SATA SSD-HDD DVD Drive Replacement (The Raid Controller is not recognized and I didn’t go through the trouble to figure that part out)


  • Download the Dell Vmware Customized ISO, I used version A01.
    • ISO: VMware-VMvisor-Installer-7.0.0-15843807.x86_64-DellEMC_Customized-A01.iso
    • SHA256: DEEEA641D8484719676D9DBC93BC92FD324FEB1FD0C6ED5975016C7E191FBB36
  • Install to non-raid controller (Single SATA), I replaced my DVD Drive with an SSD-HDD Disk Drive Caddy
  • Your R710 should be fully updated with the latest firmware.
  • You can use BIOS or UEFI mode
  • Ubuntu Live CD – ubuntu-18.04.4-desktop-amd64.iso


  1. Install ESXi media from USB or IDrac, when at the ESXI Loading Screen you have 3-4 seconds to press “SHIFT + O” to be able to edit the run boot options.
  1. Add the following value to the boot options like below. Case sensitivity matters so be accurate.


  1. Even though you will get prompted for having an unsupported CPU, you will be able to continue with the installation. If you do not see any drives, this could be due to the Dell ISO not having the required drivers to recognize your disk. ESXi 7.x removed about 50% of the drivers it used to ship with compared to older releases.
  1. Once ESXi installs you will notice upon reboot the ESXi Host will refuse to boot and once again will say you are using an unsupported CPU.
  2. To solve this. Boot with a Ubuntu Live CD 18.04 Desktop, as you will need to browse and edit two ESXi config files.
  3. Browse and edit the following files
    • BOOTBANK1/boot.cfg
    • BOOTBANK2/boot.cfg
  4. Append the following value to them allowLegacyCPU=true
  5. Make sure you save.
BootBank boot.cfg files edited with allowLegacyCPU=true

9. Once you reboot, the ESXi host should successfully load to this screen.

10. Log into your ESXi Host. When you create your virtual machine and power it on, you will get the following error. We need to set another parameter to tell ESXi to use legacy mode when creating VMs.

11. Each time you create a Virtual Machine you will need to edit the Advanced VM Configuration Options and add the key monitor.allowLegacyCPU and set it to true.

Edit Settings > VM Options > expand Advanced > Edit Configuration.

12. Once you do this, you will be able to Power On the VM. Success you have installed ESXi 7.x on an R710!