How to make a downloaded ISO bootable on Mac OS

Here are the instructions. On my system, disk4 was the USB disk.

1. Download the ISO

2. Convert it to an .img file:

hdiutil convert -format UDRW -o proxmox.img proxmox-ve_8.0-2.iso

3. Apple appends .dmg, we don’t want that. Do this:

mv proxmox.img.dmg proxmox.img

4. Figure out the USB disk number:

diskutil list

5. Unmount the disk:

diskutil unmountDisk /dev/disk4

6. Use dd as sudo to make an input file and output file of block size 1m.

Notes:

This dd write will take a while. On a Mac M2 Mini it took around 50 seconds for a 1 GB file, and almost 4 minutes for a 1.6 GB file.
Yep that’s right it says rdisk4 below. Unix guys are a bit odd.

sudo dd if=proxmox.img of=/dev/rdisk4 bs=1m

7. Eject the disk

diskutil eject /dev/disk4

Happy computing and leave us a comment if you think this article was cool.

Reference