Format a USB Flash Drive to Boot the ESXi Installation or Upgrade

Prerequisites

• 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
• Syslinux package

1: Create a partition table on the USB flash device

fdisk /dev/sdb

1. Enter d to delete partitions until they are all deleted.
2. Enter n to create a primary partition 1 that extends over the entire disk.
3. Enter t to set the type to an appropriate setting for the FAT32 file system, such as c.
4. Enter a to set the active flag on partition 1.
5. Enter p to print the partition table.

   The result should be similar to the following message.

   Disk /dev/sdb: 2004 MB, 2004877312 bytes
   255 heads, 63 sectors/track, 243 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
      Device Boot      Start         End      Blocks   Id  System
   /dev/sdb1             1           243      1951866  c   W95 FAT32 (LBA)
   

6. Enter w to write the partition table and exit the program.

2: Format the USB flash drive with the Fat32 file system

mkfs.vfat -F 32 -n USB /dev/sdb1

3: install Syslinux

wget https://mirrors.edge.kernel.org/pub/linux/utils/boot/syslinux/3.xx/syslinux-3.86.tar.gz

tar -xzvf syslinux-3.86.tar.gz

cd syslinux-3.86

apt install nasm build-essential uuid-dev mtools

make installer

mtools/syslinux /dev/sdb1

cat mbr/mbr.bin > /dev/sdb

4: Create a destination directory and mount the USB flash drive to it.