Writing the ISO to a USB Drive

The baremetal installer ISO is a hybrid image. You must write it to the USB drive in raw (DD) image mode — copying the ISO onto the drive as a file does not produce bootable media.

Use a USB drive of 32 GB or smaller. After writing the image, boot the drive in UEFI mode; the image is UEFI-only.

Choose the procedure for your workstation:

Writing the ISO in Windows
Writing the ISO in macOS

Writing the ISO in Windows

Stellar Cyber recommends Rufus for Windows workstations:

Download and run Rufus.
Set Device to your USB drive.
For Boot selection, click SELECT and choose the installer ISO.
Click START. When Rufus reports that an ISOHybrid image was detected, choose Write in DD Image mode and click OK.

If you accept the default (ISO Image mode) instead, the resulting drive does not boot.
Confirm the overwrite warning and wait for Rufus to finish.
Safely eject the USB drive.

Alternatively, you can use balenaEtcher, following the same steps described for macOS below.

Writing the ISO in macOS

Using balenaEtcher

Install and run balenaEtcher.
Click Flash from file and select the installer ISO.
Click Select target and choose your USB drive.
Click Flash.

Using the Terminal

The dd command writes to whatever device you name and does not ask for confirmation. Naming the wrong device erases that disk, including your workstation's own drive. Verify the device name and size in the diskutil list output before you run dd.

Insert the USB drive, then list the attached disks and identify the drive by its size:
Copy
```
diskutil list
```
Unmount the drive, replacing N with the disk number you identified:
Copy
```
diskutil unmountDisk /dev/diskN
```
Write the ISO. Using /dev/rdiskN (the raw device) is considerably faster than /dev/diskN:
Copy
```
sudo dd if=aella-modular-ds-<version>.iso of=/dev/rdiskN bs=4m status=progress
```
Eject the drive when the write completes:
Copy
```
diskutil eject /dev/diskN
```