You can format a USB flash drive to boot the ESXi installation or upgrade.

The instructions in this procedure assume that the USB flash drive is detected as /dev/sdb.

Note: The ks.cfg file that contains the installation script cannot be located on the same USB flash drive that you are using to boot the installation or upgrade. The kickstart file does not have any dependency on BIOS or UEFI boot.


  • Linux machine with superuser access to it
  • USB flash drive that can be detected by the Linux machine
  • The ESXi ISO image, VMware-VMvisor-Installer-version_number-build_number.x86_64.iso, which includes the isolinux.cfg file


  1. Boot Linux, log in, and enter superuser mode by using a su or sudo root command.
  2. If your USB flash drive is not detected as /dev/sdb, or you are not sure how your USB flash drive is detected, determine how it is detected.
    1. Plug in your USB flash drive.
    2. At the command line, run the command for displaying the current log messages.
      tail -f /var/log/messages
      You see several messages that identify the USB flash drive in a format similar to the following message.
      Oct 25 13:25:23 ubuntu kernel: [  712.447080] sd 3:0:0:0: [sdb] Attached SCSI removable disk

      In this example, sdb identifies the USB device. If your device is identified differently, use that identification in place of sdb.

  3. Overwrite the entire USB drive with the ISO image. This overwrites the partition table and any previous content on the USB drive.

    dd bs=10M if=VMware-VMvisor-Installer-version_number-build_number.x86_64.iso of=/dev/sdb

  4. Eject the USB drive.
    eject /dev/sdb


You can use the USB flash drive to boot the ESXi installer.