Create a Bootable ESXi Installer USB Flash Drive on macOS

In this post I’ll show how to create a bootable ESXi Installer USB flash drive on macOS without any 3rd party software. I’ve done this many times on Windows using Rufus, but here i’ll demonstrate how it can be done on macOS without 3rd party software.

See updated post Create a Bootable ESXi 7 USB Installer on macOS with video.


  • Download the ESXi Installation ISO (I used ESXi 6.7 Update 3)
  • A USB Flash Drive Minimum 8GB

Step 1

Open Terminal and list the mounted disks using the diskutil list command.

diskutil list

Step 2

Insert the USB Flash then run the diskutil list command again.

diskutil list

You should now see another disk show up, in my case disk3. Take note for the disk#.

Step 3

Now we need to format the drive with filesystem FAT32 and partition map MBR using the following command. Don’t forget to use the disk# number obtained in step 2.

diskutil eraseDisk MS-DOS "ESXI" MBR disk#

Step 4

Unmount the USB Drive, Note: This is not the same as Eject. Don’t forget to use the disk# number obtained in step 2.

diskutil unmountDisk /dev/disk#

Step 5

Start the command line partitoner fdisk in interactive mode (You will need administrative privileges for this).

sudo fdisk -e /dev/disk#
  1. Flag the first partition on the volume as active and bootable. “f 1
  2. Write the changes. “write
  3. Quit fdisk. “quit
f 1

Step 6

Mount the ESXi Installation ISO and copy all the contents from the ISO to the USB flash drive.

Step 7

Locate the file ISOLINUX.CFG on the flash drive and rename it SYSLINUX.CFG file.

Step 8

Edit the SYSLINUX.CFG file with TextEdit, Don’t use a Word program it will mess up the file. Find the line starting with APPEND -c boot.cfg and append -p 1 to it.

APPEND -c boot.cfg -p 1

Save and close the file and eject the USB flash drive.

Step 9

I booted the ESXi installer on my Intel NUC Skull Canyon successfully.

Here’s a Tip! the installer loads the files into memory so you can choose the same USB drive to install ESXi and boot from. Hope you enjoyed this guide.

8 comments Add yours
  1. Please disregard, the file must be hidden or something. I can’t see it using Finder, but it’s there if I use Terminal app

  2. i have got corrupted usb drive image, i will need to make new usb bootable 6.5 image to load it again. should i re-install again and complete the configuration as fresh or just load it from bootable usb then host will continue with previous installations?

  3. Thanks for the share. Running into an error where I’ve attempted multiple times to get this to work but am running into just a flashing cursor post eject of USB drive. So it loads (double checked the boot priority in BIOS) to just a flashing cursor. I’m using on-board HDMI (I’ve seen rumblings of possible graphics related issue), but outside of that, no idea why it’s not loading to install. Any thoughts?

    1. I can only suggest trying another USB flash drive, I’ve not come across that problem before. Do you have any other options to install it, like Pxe or USB CD-ROM drive?

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